Kawasaki Concours Forum

Mish mash => Open Forum => Topic started by: Tree on July 14, 2017, 06:50:40 pm

Title: Math Question
Post by: Tree on July 14, 2017, 06:50:40 pm
TO ALL OF THE MATH NERDS OUT THERE:  I need help with the math.  If I averaged 32 mpg prior to the flash, and I am now getting what these photos suggest, how long will it take for the EVO flash to pay for itself?  What, if any, other information do you need to get the answer?

I'm bored.  Humor me.

Title: Re: Math Question
Post by: B.D.F. on July 14, 2017, 07:38:11 pm
First of all, your display is broken. What are those words showing.... "FUEL LOW" and why are they there?  There, you can humor me back.  ;D

OK, 218.6 miles, divided by 4.807 gal., carry the two, square the result and factor in the Coriolis effect and I get.... 45.4753 MPG. Which does not make any sense if the only change was a re-flashed ECU but as you said, I am humoring you: 45.5 / 32 (forgive the rounding, you have bigger errors anyway) yields a ratio of: 1.4211. Now we take the cube root, convert to base 8 and the answer is.... I need to know how much the flash cost. There, it will take <some> miles to pay <some> amount for what is <not> resulting in a ~ 50% increase in fuel economy.

Hey, that was humorous.

Assuming the cost of fuel remains constant, we are going to have to do a little bit more math and fill in some of the unknown variables (flash cost) to answer your question. Inside of every large problem, a small problem is struggling to get out. Inside your current large problem (when you will be back in the black), the small problem is we need to know the cost of the flash. But I have my abacus all dusted off and ready to slide the balls as needed to get you a solution.

I do know how you can use more of the available fuel tank on that bike right now though.  :rotflmao:

Brian (and people think math is not fun. Sheesh!)

TO ALL OF THE MATH NERDS OUT THERE:  I need help with the math.  If I averaged 32 mpg prior to the flash, and I am now getting what these photos suggest, how long will it take for the EVO flash to pay for itself?  What, if any, other information do you need to get the answer?

I'm bored.  Humor me.
Title: Re: Math Question
Post by: tweeter55 on July 14, 2017, 07:50:30 pm
 It is costing you approximately 2.889 cents per mile less now than it did before the flash.  At least, that's the number I'm coming up with.
Title: Re: Math Question
Post by: B.D.F. on July 14, 2017, 07:57:04 pm
Excellent! Hey, between the two of us, I bet we could guess what the flash cost and give the OP a well calculated, incorrect answer!

Now I am humoring myself but will stop before I go blind.

Brian

It is costing you approximately 2.889 cents per mile less now than it did before the flash.  At least, that's the number I'm coming up with.
Title: Re: Math Question
Post by: B.D.F. on July 14, 2017, 08:17:24 pm
You will save $350,  based entirely on those fuel costs and consumption you specified, in almost exactly 12,000 miles. $400 difference will occur at ~13,830 miles.

Again, I do not know what flash you have nor what it cost but one those two numbers ought to be close I think.

Hey, where did you go? You did not even stay around for the amusement.   ;D

Brian

TO ALL OF THE MATH NERDS OUT THERE:  I need help with the math.  If I averaged 32 mpg prior to the flash, and I am now getting what these photos suggest, how long will it take for the EVO flash to pay for itself?  What, if any, other information do you need to get the answer?

I'm bored.  Humor me.
Title: Re: Math Question
Post by: maxtog on July 14, 2017, 09:39:05 pm
45.4753 MPG. Which does not make any sense if the only change was a re-flashed ECU but as you said, I am humoring you: 45.5 / 32

Agreed.  There are other factors at work.  No ECU flash is going to account for a difference in 13.5 MPG on the C14.  Either one or more of the measurements are inaccurate (more likely), or the style/type of riding changed drastically (less likely).  I would believe up to maybe 4MPG without much question.  5-6 with a little caution.  Anything higher with major skepticism.
Title: Re: Math Question
Post by: Tree on July 14, 2017, 10:30:53 pm
Wow.  I think I touched a couple of nerves.  I paid $375 for the flash (SISF).  I rode at 80 mph highway for most of the miles commuting to/from work on straight flat slab.  The mileage is from 2 days of round trips.  I already know that the flash yielded improved fuel economy but there are other factors that bumped it up.  One being that I had to make an effort to not goose the throttle and play with the bike like I normally do.  Another factor being I stayed out of the hills and away from the twisties, so no rapid acceleration from this tank.

Thank you for taking the time to crunch the numbers and for minimizing the abuse.  I have never seen the trip ODO above 160 before being compelled to fuel up.  That was cool to see.  Will the flash pay for itself based upon improved fuel economy?  Probably in less than a year?

So ends the math problem and an aborted attempt at a bit of levity.

Tree
Title: Re: Math Question
Post by: maxtog on July 14, 2017, 10:57:49 pm
One being that I had to make an effort to not goose the throttle and play with the bike like I normally do.  Another factor being I stayed out of the hills and away from the twisties, so no rapid acceleration from this tank.

That can do it.

Quote
Will the flash pay for itself based upon improved fuel economy?

Yes.... eventually

Quote
Probably in less than a year?

Very unlikely.  I tend to see the 42MPG number as an average of averages for the C14, highway miles, stock.  So let's say you actually had an improvement of more like 3MPG.  Gas price varies a lot, but let's use $2.50/gal.  That is a change between $0.0595 to $.0555 per mile which is 0.4 cents per mile.  So $375 would be paid for in 93,750 miles.  Which, in my case (being I ride only about twice a week for a few hours each), would take about 20 years :)  If the improvement were 6MPG (which would be stretching it), it would take 46,875 miles.   
Title: Re: Math Question
Post by: B.D.F. on July 15, 2017, 04:15:21 am
?? ?? I think we have had some kind of miss- communication: I thought the whole thread was very amusing and did my best to bat the ball back over the net. ?? Probably those fine divisors between humor, sarcasm, twisted observances and similar that just do not play well with the written word, or at least the great unwashed is doing the writing (meaning me, not you or anyone else- this is exactly how you could take it as an insult while it was really a self- depreciating remark about my own limitations).

Fun, humor, not always so easy to see on the 'Net. Not speaking for anyone else, but nothing in this thread and nothing you said or asked 'touched a nerve'. I thought it was amusing and was trying to respond in kind. You made reference to 'math nerd' and 'humor me', so I responded with my best rendition of 'nerd' and did humor you; I was chuckling a bit as I responded. So again, this entire thread struck me as amusing and for dessert, I believe I answered your question, as best I could without knowing the cost. BTW, given the cost, the mileage you ask about is, I believe (may have made a mistake or three but I think this is right) 12,963 miles.

Again, I do not believe your attempt at levity was missed and certainly not mistaken for something offensive in the least. Humor and a bit of comradeship is WHY I participate here and I love running into posts such as yours. By all means, please do continue to post and whenever possible, throw in something that is amusing, even if it is only to amuse yourself.... and those of us who can or will will follow along.

Anyway, back on the bigger topic: things like this (the flash) are really hard to pin down as to how much they save; as you said, different types of riding, etc. mean a lot comparing a stock ECU with one that has been altered. Just my own opinion but while the money saved is all fine and well, I would be more interested in how I liked the thing directly; if you like the bike with the ECU flashed, and are going to keep it for a while, then that alone is more than worth the cost in my opinion. Then again, if you like the flash and actually ride the bike harder (Easy Boys!) because of it and actually LOSE some economy, that is a win in my opinion also. These bikes are too big, too tough on tires, too expensive to maintain to really use economy as a factor in owning or riding one; the fact is I can drive an SUV for less cost per mile than a C-14 but I do not think of it that way.

Anyway, as I said, no nerves touched on my end and absolutely no negative take- away from  your original post. Keep posting and I think you will find both that this is a nice, friendly forum and that a good deal of its charm is the sideways humor.

Brian

Wow.  I think I touched a couple of nerves.  I paid $375 for the flash (SISF).  I rode at 80 mph highway for most of the miles commuting to/from work on straight flat slab.  The mileage is from 2 days of round trips.  I already know that the flash yielded improved fuel economy but there are other factors that bumped it up.  One being that I had to make an effort to not goose the throttle and play with the bike like I normally do.  Another factor being I stayed out of the hills and away from the twisties, so no rapid acceleration from this tank.

Thank you for taking the time to crunch the numbers and for minimizing the abuse.  I have never seen the trip ODO above 160 before being compelled to fuel up.  That was cool to see.  Will the flash pay for itself based upon improved fuel economy?  Probably in less than a year?

So ends the math problem and an aborted attempt at a bit of levity.

Tree
Title: Re: Math Question
Post by: B.D.F. on July 15, 2017, 04:22:25 am
Just went back and re-read this thread: my posts are fully of smileys. I tried to show that I was being humorous.

BTW, the references to you display being broken and knowing how you could get more miles out of  a tank of fuel were left- hand references to a product I sell that modifies that part of the bike. Again, self- referencing stabs at humor, not digs at you or your bike, and I try not to hawk my products too much on the forum so I usually do not mention directly any references to them. That part may have been missed if you are not aware of them and may <seem> like sarcasm but really, it was not meant that way at all.

Brian
Title: Re: Math Question
Post by: Tree on July 15, 2017, 06:38:14 am
These board postings will never replace actual spoken verbal communication between us humans.  Stuff gets lost in translation and time.

Brian, I appreciate that you replied further and made an effort to smooth any perceived ruffled feathers.  I find it funny to note that shortly after I posted this math problem that it was replied to so quickly and repeatedly.  I didn't have the chance to participate in the traditional back and forth banter because I was away from the house for a few hours.  For you, I would guess, it's very much like sending a text to someone and expecting a reply that never comes (in the time frame that one expected).  Sometimes, for me anyhow, the longer it takes for me to receive a reply the more agitated I can get because of my expectations.  Then there are the tricks that my mind often plays with me while I impatiently wait for a response.  I will totally create some truly horrible alternative reasons as to why I had not heard from a person to whom I had reached out to and wrap myself around the proverbial axle.  That's something I'm going through at this time as a matter of fact.

I enjoyed reading the replies and found myself way behind in a conversation that took on a life of its own.  I missed out on the exchange of jabs and parries.  I further appreciate the time it took to put pencil to paper (finger to calculator) to crunch numbers.  Did I check your math?  Hell no!  That would have been an insult.  Besides, I trust that your abacus is accurate and has been calibrated to NIST standards.   Coriolis effect, really?  ;D

Tree
Title: Re: Math Question
Post by: Conniesaki on July 15, 2017, 08:16:42 am
Just went back and re-read this thread: my posts are fully of smileys. I tried to show that I was being humorous.

...

Yeah, but ... but ... I thought those were sarcastic smileys  ???
Title: Re: Math Question
Post by: B.D.F. on July 15, 2017, 09:44:53 am
Nope. Do we have sarcastic smiles?

Hey Jim, can we get some sarcastic smiles around here?

 ;D

Brian

Yeah, but ... but ... I thought those were sarcastic smileys  ???
Title: Re: Math Question
Post by: B.D.F. on July 15, 2017, 10:12:06 am
It can get pretty close to in- person interaction but it takes longer to get to know the personalities involved. Also, just like in person, at least some people respond differently to different people. This thread is actually a good example of that: I actually responded a bit more sharply than I usually would, and maybe should have, to you, who I do not really know well at all.

Internet forums do have a tremendous advantage over personal contact in one way, we can all correspond with others sharing a similar interest literally all over the globe. I have been here since buying a relatively early C-14 in '07 and the internet community that formed around that new model was tremendously successful in learning about, and modifying the bike. Especially because it was a relatively advanced model with things such as the dreaded KiPass (read: bad ju-ju). I know I could have never gained as much knowledge probably ever, and certainly not what we collectively learned in, say, the first year, with only those C-14 owners I could talk with in person. And the fact is that while the perceived anonymity of the 'Net does bring out some pretty callous behavior, it also provides the occasional 'diamond' of information; when I was learning how to hang a Rostra on a C-14, there was a gentleman who had done a tremendous amount of truly excellent work on that device (the Rostra) while pioneering the install on an older Goldwing. A learned a lot about the unit from him even though most of it did not apply directly to a C-14. If memory serves, he was in southern California and I NEVER would have heard of him or his work without forums such as this one.

The time thingy is a bit of a problem because it is 'all over the place' with some replies going back and forth w/in minutes and other exchanges taking days. Same thing with e-mails; I correspond with a fair number of people about motorcycle stuff, mostly but not all C-14, and I just never know when I will get a response, if I will get a response, and if the response will contain information, progress, just more questions, a request for clarification on previous answers, etc.. One of the real problems is trying to strike that fine balance between complete explanation, sufficient to get the task accomplished, and too much simplification which wastes time and often annoys the other person who thinks he / she is being 'talked down to'. But how can I possibly know what another person knows, and where to start off with an explanation? Is saying 'splice into the gray wire' enough or does that person need more detailed instruction on how to splice? Can that person solder and does he / she have soldering tools? I have no idea. Organized education is way ahead because when going into 5th grade, it is assumed the student has completed grades 1 to 4 but when I help someone with a motorcycle problem, I have absolutely no idea at what level we are starting. BTW: I am in the middle of a house project and am now on the receiving end of that very situation, having electricians explain to me that residential power is "two phase" and so forth.

Coriolis effect: I like to participate in bowling pin shoots; really very simple, bowling pins are placed on a rigid plate, usually 5 pins per station, two stations next to each other and 'hot' at the same time. First one to clear all the pins from the stand wins that heat (and they have to be cleared, no knock- downs allowed if the pin is lying on the stand). At some ranges, the 'studio' audience calls out helpful suggestions (read: obnoxious insults, ridiculous 'facts', etc.) and one day someone called out to a shooter, after he had lost embarrassing badly, that perhaps he forgot to compensate for the Coriolis effect. The pins are 30 feet from the firing line, and just mentioning that struck me as funny enough that I thought I was going to wet my pants a little. Now the Coriolis effect does very much matter to some shooters but only after about 600 yards, and always with things such as artillery but not so much at 30 feet.  :rotflmao:

Brian

These board postings will never replace actual spoken verbal communication between us humans.  Stuff gets lost in translation and time.

Brian, I appreciate that you replied further and made an effort to smooth any perceived ruffled feathers.  I find it funny to note that shortly after I posted this math problem that it was replied to so quickly and repeatedly.  I didn't have the chance to participate in the traditional back and forth banter because I was away from the house for a few hours.  For you, I would guess, it's very much like sending a text to someone and expecting a reply that never comes (in the time frame that one expected).  Sometimes, for me anyhow, the longer it takes for me to receive a reply the more agitated I can get because of my expectations.  Then there are the tricks that my mind often plays with me while I impatiently wait for a response.  I will totally create some truly horrible alternative reasons as to why I had not heard from a person to whom I had reached out to and wrap myself around the proverbial axle.  That's something I'm going through at this time as a matter of fact.

I enjoyed reading the replies and found myself way behind in a conversation that took on a life of its own.  I missed out on the exchange of jabs and parries.  I further appreciate the time it took to put pencil to paper (finger to calculator) to crunch numbers.  Did I check your math?  Hell no!  That would have been an insult.  Besides, I trust that your abacus is accurate and has been calibrated to NIST standards.   Coriolis effect, really?  ;D

Tree
Title: Re: Math Question
Post by: VirginiaJim on July 15, 2017, 01:10:16 pm
Nope. Do we have sarcastic smiles?

Hey Jim, can we get some sarcastic smiles around here?

 ;D

Brian

Someone shows me a sarcastic smiley and I'll get it...

As far as the flash goes, my MPG improved by several miles a gallon.  I don't know about math..

This isn't a smiley but it reminds me of Poke.
Title: Re: Math Question
Post by: maxtog on July 15, 2017, 01:55:05 pm
As far as the flash goes, my MPG improved by several miles a gallon.  I don't know about math..

The math is boring.  The riding is fun :)  Sure, increased MPG seems to be a fact with Steve's flash (I think the Guhl flash only helped maybe 2MPG, if that), and that is great!  But like Brian said, the cost pales in comparison to the fun factor.  Of course, knowing it helps to pay for itself doesn't hurt either..... especially if someone else is watching your wallet  :o

So... an investment in fun?
Title: Re: Math Question
Post by: gPink on July 15, 2017, 04:02:10 pm
Should be a fedgov subsidy for the flash since it improves mileage therefore reduces the carbon footprint.
Title: Re: Math Question
Post by: B.D.F. on July 15, 2017, 04:24:10 pm
Good idea- as soon as you get the 'new ECU' type- approved by DOT for use in the US, go and see if you can get a $0.11 / vehicle EPA discount.

 :rotflmao:

We cannot even alter our headlights w/out violating DOT standards, never mind control the engine.

Brian

Should be a fedgov subsidy for the flash since it improves mileage therefore reduces the carbon footprint.
Title: Re: Math Question
Post by: maxtog on July 15, 2017, 08:33:04 pm
Should be a fedgov subsidy for the flash since it improves mileage therefore reduces the carbon footprint.

Yeah, they will get to that right after banning motorcycles for being "gross polluters", "unsafe", and non-self-driving...
Title: Re: Math Question
Post by: maxtog on July 15, 2017, 08:34:44 pm
We cannot even alter our headlights w/out violating DOT standards, never mind control the engine.

And yet the first thing that perhaps 90%+ of motorcycle owners do is immediately slap on an illegal/unapproved muffler to make the machine "louder" so it "performs" better.   ::)
Title: Re: Math Question
Post by: B.D.F. on July 15, 2017, 08:53:55 pm
HIGH THREAD DRIFT CURRENTS AHEAD:

Interesting thing going on in some cities and towns where I live, regarding aftermarket exhausts and LEOs. A twist of the application of the law for a totally unintended consequence.

Exhausts, just like vehicle outside lighting, etc., are all type certified by DOT. The exhaust systems on motorcycles have a very small stamped number showing that they are type certified for, say a C-14 (but not a ZX 14: swapping one for the other is NOT legal). Now normally LEO's just do not bother with this at all. But after the last decade or two of motorcycles pounding the eardrums out of the mass population, some communities have decided they have had enough. And those cities and towns are well posted that if you violate exhaust rules, there will be harsh penalties (large fines). Now for the twist: LEOs stop excessively loud motorcycles of a type and brand we all know, then look at the exhaust for that type certification.... and of course, as an aftermarket system, it is not here. And then the truly painful ticket for a non- conforming exhaust. Note that they are never charged / fined / accused for excessive noise.

This system actually works and seems to be, so far, a workable loophole. Now, it is in fact the noise that causes the stop in the first place, and the actual desire to cause the fine but is not used as a reason because there are strict parameters for a noise test. But the same check is just not performed on any motorcycle that does not rattle anyone's windows on the way by. I guess we could call it 'selective enforcement' of a valid law.

Over the last few years this really proving to be effective; those two cylinder, miss- timed thumping bikes may still have a bit of a growl but nothing like it used to be.

It ain't quite right, and is not and never was the intent of the law but it does work and so far, has not been challenged as discriminatory. Probably all because those running at 100+ decibels know they are 'coloring outside the lines' in the first place. Plus it is hard to challenge the fact that excessive noise was probable cause for a stop but was not used in any way to issue a citation.

Brian
And yet the first thing that perhaps 90%+ of motorcycle owners do is immediately slap on an illegal/unapproved muffler to make the machine "louder" so it "performs" better.   ::)
Title: Re: Math Question
Post by: Tree on July 15, 2017, 10:22:00 pm
The wonderful Morphing Thread.  I swear, all I did was to go out and check the mail and come back to find we are now talking about exhausts/noise.  What happens when I go away for a short while to, say, chase a raccoon out of the garage?  Are we then gonna be talking about coconuts and the capabilities of African Vs. European swallows to carry them?  Which, come to think of it, would be fun.  I love a good Python goof.   :P
Title: Re: Math Question
Post by: maxtog on July 16, 2017, 02:41:39 am
But after the last decade or two of motorcycles pounding the eardrums out of the mass population, some communities have decided they have had enough. And those cities and towns are well posted that if you violate exhaust rules, there will be harsh penalties (large fines).

I certainly wish they would do that here.  And throw in boom-box cars, too.

The wonderful Morphing Thread.  I swear, all I did was to go out and check the mail and come back to find we are now talking about exhausts/noise. 

You gotta keep up!!
Title: Re: Math Question
Post by: mikeyw64 on July 16, 2017, 03:59:50 am

Staying on the exhaust front , over here  a pre 1983 bike doesn't need any sort of mark on it nor is it subject to any decibel limit ,.


Post 1983 as lon as the exhaust is stamped with the relevant British STandard or equivalent International kite mark then you're good. Ther eis a 80db level for new bikes from 97 onwards  however for the annual MOT it must not be "excessivly noisy" (which is at the testers discretion)


Either way if the can has "Not for Road/Highway Use" stamped on it then it is not legal.


HIGH THREAD DRIFT CURRENTS AHEAD:

Interesting thing going on in some cities and towns where I live, regarding aftermarket exhausts and LEOs. A twist of the application of the law for a totally unintended consequence.

Exhausts, just like vehicle outside lighting, etc., are all type certified by DOT. The exhaust systems on motorcycles have a very small stamped number showing that they are type certified for, say a C-14 (but not a ZX 14: swapping one for the other is NOT legal). Now normally LEO's just do not bother with this at all. But after the last decade or two of motorcycles pounding the eardrums out of the mass population, some communities have decided they have had enough. And those cities and towns are well posted that if you violate exhaust rules, there will be harsh penalties (large fines). Now for the twist: LEOs stop excessively loud motorcycles of a type and brand we all know, then look at the exhaust for that type certification.... and of course, as an aftermarket system, it is not here. And then the truly painful ticket for a non- conforming exhaust. Note that they are never charged / fined / accused for excessive noise.

This system actually works and seems to be, so far, a workable loophole. Now, it is in fact the noise that causes the stop in the first place, and the actual desire to cause the fine but is not used as a reason because there are strict parameters for a noise test. But the same check is just not performed on any motorcycle that does not rattle anyone's windows on the way by. I guess we could call it 'selective enforcement' of a valid law.

Over the last few years this really proving to be effective; those two cylinder, miss- timed thumping bikes may still have a bit of a growl but nothing like it used to be.

It ain't quite right, and is not and never was the intent of the law but it does work and so far, has not been challenged as discriminatory. Probably all because those running at 100+ decibels know they are 'coloring outside the lines' in the first place. Plus it is hard to challenge the fact that excessive noise was probable cause for a stop but was not used in any way to issue a citation.

Brian
Title: Re: Math Question
Post by: Classvino on July 17, 2017, 10:00:23 am
I certainly wish they would do that here.  And throw in boom-box cars, too.

Since this topic seems to be wandering, I'll throw in a related (hopefully amusing) tale...

We had a townhouse at the end of a row of townhouses, and just over the fence was a convenience store that was turning into a hangout for 3 or 4 cars with LOUD stereos, and they liked to compare volumes between the vehicles, and apparently the best time of day to do that was just after the store closed - around midnight... 

To further exacerbate the problem, they did seem somewhat concerned about their hearing, and were wearing earplugs so as not to deafen themselves inside the vehicle, despite not worrying about the affects to anyone else's hearing (say in a 200 yard radius or so...) This just made it possible for them to turn up the volume way past the pain threshold inside (or even near) their vehicles.

One night I wandered over and pretended to admire the "noise" until close enough to be invited to lean into the window to "see" the equipment, at which time I pulled out a "canned-air horns" from a pocket. and shoved my arm into the car, where a couple "loud-stereo" owners were sitting, and pulled the trigger, emitting a >100  decibel blast.  The occupants had removed their earplugs to be able to speak with me without resorting to anything so crass as shouting...

It didn't go over well...  I was accused of attempting to deafen them, and castigated for showing no concern for their "aural" well-being.
(I was even threatened with physical violence - but being twice the size of any one of them, it was not a great worry of mine, and it was just bluster in any case. (Could have been worse, I guess, but I hadn't considered that... maybe stupid on my part...)

At this point, I mentioned that several of us in the development had been discussing possible solutions, and that this one had seemed at the time, to be the most pacifistic (and least likely to produce assault charges), and that to avoid any escalation, they might pick another location to demonstrate the abilities of their sound systems.

They did.

I still can't forget the looks on their faces as I held the horn inside their vehicle - it must've lasted 15 seconds or so before they overcame their shock and incredulity and pushed the horn away...  To quote the credit card commercial,  ...priceless...

Disclaimer : I won't normally suggest any sort of vigilante action, but with 2 toddlers in the house being woken up every other night for a couple weeks by these guys, and having the bylaw officer not showing up on any of several occasions, I was angry enough to implement this plan. Fortunately it worked.

Jamie
Title: Re: Math Question
Post by: B.D.F. on July 17, 2017, 11:10:12 am
Yeah.... kids.

The biggest problem with things such as this example is that the anger builds and builds without those causing it to realize it (the anger) is even happening. Unfortunately, this all too often results in the very first meeting of the annoyed and the annoy-er(s) being very heated. No one's fault really (assuming the kids were just young, foolish and inconsiderate as most kids are, and not really trying to provoke outright hostility), just the result of people living close together and behaving as if they were not affecting anyone else.

Kinda' like a road rage incident without the road part.

Glad that worked out OK for you and 'them'. Often, it does not work out for either party; one suffers immediately while the other one suffers over a longer period of time because 'the wheels of justice turn slowly'.

Brian

Since this topic seems to be wandering, I'll throw in a related (hopefully amusing) tale...

<snip>

Disclaimer : I won't normally suggest any sort of vigilante action, but with 2 toddlers in the house being woken up every other night for a couple weeks by these guys, and having the bylaw officer not showing up on any of several occasions, I was angry enough to implement this plan. Fortunately it worked.

Jamie
Title: Re: Math Question
Post by: B.D.F. on July 17, 2017, 12:27:46 pm
Well, seeing as we do not seem to be dealing with math much, let's move onto the nerd part.

The Coriolis effect is usually very difficult to detect, does not generally make itself obvious and we just about ignore it. But now and again, it shows up and when it does, is almost always is a big enough problem that it cannot be ignored.

Artillery always has to contend with the Coriolis effect, and the longer than range, the worse the effect. The worst case would be the longest range gun ever used, know as the Paris gun used to shell Paris (duh) by the Germans, from behind their lines, during WWI. The gun had a range of just over 80 miles (!!!) and the projectile had a flight time of three minutes. The Coriolis effect is really quite simple: as the Earth rotates, what appears to be a fixed target, such as Paris (it does not appear to be moving), actually is moving and travels a significant distance during that gun's projectiles' travel time. Calculations show that without compensating for this effect, the point of impact would be moved ~ one kilometer, well over 1/2 mile, from point of aim.

For all your nerdiness needs: http://www.vcsp.info/Chapter_8/Application_to_Long-Range_Artillery_-_Shelling_Paris_in_WW1/Shell_Trajectory_in_Atmosphere_on_a_Rotating_Earth.aspx (http://www.vcsp.info/Chapter_8/Application_to_Long-Range_Artillery_-_Shelling_Paris_in_WW1/Shell_Trajectory_in_Atmosphere_on_a_Rotating_Earth.aspx)

And that was not a big gun such as Schwerer Gustav was either.  :yikes:

Brian
Title: Re: Math Question
Post by: Rhino on July 17, 2017, 01:55:37 pm
Well, seeing as we do not seem to be dealing with math much, let's move onto the nerd part.

The Coriolis effect is usually very difficult to detect, does not generally make itself obvious and we just about ignore it. But now and again, it shows up and when it does, is almost always is a big enough problem that it cannot be ignored.

Artillery always has to contend with the Coriolis effect, and the longer than range, the worse the effect. The worst case would be the longest range gun ever used, know as the Paris gun used to shell Paris (duh) by the Germans, from behind their lines, during WWI. The gun had a range of just over 80 miles (!!!) and the projectile had a flight time of three minutes. The Coriolis effect is really quite simple: as the Earth rotates, what appears to be a fixed target, such as Paris (it does not appear to be moving), actually is moving and travels a significant distance during that gun's projectiles' travel time. Calculations show that without compensating for this effect, the point of impact would be moved ~ one kilometer, well over 1/2 mile, from point of aim.

For all your nerdiness needs: [url]http://www.vcsp.info/Chapter_8/Application_to_Long-Range_Artillery_-_Shelling_Paris_in_WW1/Shell_Trajectory_in_Atmosphere_on_a_Rotating_Earth.aspx[/url] ([url]http://www.vcsp.info/Chapter_8/Application_to_Long-Range_Artillery_-_Shelling_Paris_in_WW1/Shell_Trajectory_in_Atmosphere_on_a_Rotating_Earth.aspx[/url])

And that was not a big gun such as Schwerer Gustav was either.  :yikes:

Brian


So we need to know if Tree was traveling along a longitudinal or on a latitude line to figure out if the corollas effect effected his mileage to more accurately determine the break even point with the flash  ;D
Title: Re: Math Question
Post by: B.D.F. on July 17, 2017, 02:43:35 pm
Right. And maybe even more importantly, he may not have been where he thought he was when he filled up his fuel tank in the first place.

The plot thickens....

Brian

So we need to know if Tree was traveling along a longitudinal or on a latitude line to figure out if the corollas effect effected his mileage to more accurately determine the break even point with the flash  ;D
Title: Re: Math Question
Post by: VirginiaJim on July 17, 2017, 03:54:53 pm
Well, seeing as we do not seem to be dealing with math much, let's move onto the nerd part.

The Coriolis effect is usually very difficult to detect, does not generally make itself obvious and we just about ignore it. But now and again, it shows up and when it does, is almost always is a big enough problem that it cannot be ignored.

Artillery always has to contend with the Coriolis effect, and the longer than range, the worse the effect. The worst case would be the longest range gun ever used, know as the Paris gun used to shell Paris (duh) by the Germans, from behind their lines, during WWI. The gun had a range of just over 80 miles (!!!) and the projectile had a flight time of three minutes. The Coriolis effect is really quite simple: as the Earth rotates, what appears to be a fixed target, such as Paris (it does not appear to be moving), actually is moving and travels a significant distance during that gun's projectiles' travel time. Calculations show that without compensating for this effect, the point of impact would be moved ~ one kilometer, well over 1/2 mile, from point of aim.

For all your nerdiness needs: [url]http://www.vcsp.info/Chapter_8/Application_to_Long-Range_Artillery_-_Shelling_Paris_in_WW1/Shell_Trajectory_in_Atmosphere_on_a_Rotating_Earth.aspx[/url] ([url]http://www.vcsp.info/Chapter_8/Application_to_Long-Range_Artillery_-_Shelling_Paris_in_WW1/Shell_Trajectory_in_Atmosphere_on_a_Rotating_Earth.aspx[/url])

And that was not a big gun such as Schwerer Gustav was either.  :yikes:

Brian


So if I could hover in the air over a fixed spot for a few days, does that mean that spot will eventually move away from me?
Title: Re: Math Question
Post by: Rhino on July 17, 2017, 04:33:36 pm
So if I could hover in the air over a fixed spot for a few days, does that mean that spot will eventually move away from me?

The corollas effect doesn't have as much to do with the fact that the target is moving (so is the gun) but the fact that due to the curvature of the earth it is moving at a different rate if it is at a different latitude.
Title: Re: Math Question
Post by: olie on July 17, 2017, 05:07:59 pm
Should be a fedgov subsidy for the flash since it improves mileage therefore reduces the carbon footprint.
... for sure the Flashing developers have tested all those compete emissions to be in compliance with EPA and EU Directives  ;)  .... probably they sell the magic Flash just to be used just on the race tracks ;)

For some it is time to get Leaded Gas, no Sulfur restriction, no APC systems, open exhausts, etc... for those it will be the time to smell those exhausts.
Title: Re: Math Question
Post by: maxtog on July 17, 2017, 05:53:21 pm
... for sure the Flashing developers have tested all those compete emissions to be in compliance with EPA and EU Directives  ;)  .... probably they sell the magic Flash just to be used just on the race tracks ;)

Yeah, I always love those [necessary] disclaimers "to be used off-road only" "race-track use only".  To sell it outright for general use or at a dealer or something would require extensive and expensive testing and probably would not pass anyway.  One of the reasons performance is hurt by factory programming is exactly to pass restrictive emissions, fuel economy, and noise regulations.

I could feel the exact same lack-luster dead zone in the Concours, pre-flash, that I had on my previous bike, *carbureted* ZRX-11 (which was fixed with the mechanical equivalent of some of the ECU flashing- a "jet kit").
Title: Re: Math Question
Post by: B.D.F. on July 17, 2017, 06:21:20 pm
Yeah, what Max said although I would put a little different twist on it: very small amounts of 'violation' are tolerable and ignored. There just are not enough C-14's that are ever going to get their ECU's altered that it will make any difference to the planet and so it will not get the EPA's attention. Sort of the way speeding is illegal but no one cares about a 'few' MPH over the technical limit but serious offenders are ticketed.

The aftermarket 'engine controls' modifiers are not all immune though because if it gets scaled up, it does show up and draws attention as well as sanctions. Take DynoJet, they sell aftermarket vehicle add- on engine control modifying hardware but it can be used on a great many motorcycles rather than just one model (C-14) of one brand (Kawasaki). So stamping something that violates EPA rules of road use with 'For off- road use only' no longer works as an escape clause. The state of California successfully sued DynoJet for selling these 'off road' units to more vehicles than exist in the state for track use in the first place, which basically destroyed DynoJet's excuse that they had no idea these units were being used illegally, on road vehicles. If memory serves, the settlement was seven- digits and installed limits on future business w/in the state.

Brian

... for sure the Flashing developers have tested all those compete emissions to be in compliance with EPA and EU Directives  ;)  .... probably they sell the magic Flash just to be used just on the race tracks ;)

For some it is time to get Leaded Gas, no Sulfur restriction, no APC systems, open exhausts, etc... for those it will be the time to smell those exhausts.
Title: Re: Math Question
Post by: gPink on July 17, 2017, 06:31:56 pm
... for sure the Flashing developers have tested all those compete emissions to be in compliance with EPA and EU Directives  ;)  .... probably they sell the magic Flash just to be used just on the race tracks ;)

For some it is time to get Leaded Gas, no Sulfur restriction, no APC systems, open exhausts, etc... for those it will be the time to smell those exhausts.

wow, can we buy leaded gas again? I'll have to get rid of the cat but it'll be worth it.  ::)
Title: Re: Math Question
Post by: B.D.F. on July 17, 2017, 06:39:30 pm
That definitely is a problem if the trajectory crosses a lot of latitude but even if the trajectory is directly in- line with the equator, the Coriolis effect will cause a ballistic trajectory to fall significantly short or go significantly long; both ways miss the target entirely.

The root problem is that if two distant objects are connected, all is well but when a projectile leaves the muzzle of the launching device, it is no longer being held at the velocity of the rotating planet and so slows its original velocity in the direction of Earth's rotation in flight. The target though is still connected to Earth, continues to maintain rotational speed and basically moves away from the place the projectile is now headed for. If there were a set of rails connecting the two points (launch point and desired landing point) and the projectile rode along those rails, the Coriolis effect again would not be noticed.

But all of this follows much, much bigger problems starting with the ability to build a device, rifle or artillery, that will generate the problem in the first place, and then having the abilities, both skill as well as sufficient optics for sighting, range- finding, etc., to have the trajectory problem in the first place. If Krupp could design and make the artillery, and they did, then they could certainly dig up a nerd with a slide rule to tell the A- gunner where to REALLY aim. And most ordinary humans with the finest small- arms available simply do not have the skill to have this effect be the or 'a' major problem; the very best of us (humans) can put 10 rounds onto a target at 1,000 meters (~ 5/8 of a mile) into a group UNDER 3".... something I am pretty happy with at 300 yards on my better days.

Brian

The corollas effect doesn't have as much to do with the fact that the target is moving (so is the gun) but the fact that due to the curvature of the earth it is moving at a different rate if it is at a different latitude.
Title: Re: Math Question
Post by: B.D.F. on July 17, 2017, 06:41:05 pm
Absolutely, and you always could. Stop by the local airport and pick up some 100 octane LL AvGas. The LL stands for Low Lead but do not let that fool you- there is a lot of lead in the stuff, just like in the olden' days. Get all you want, bring money.

Brian

wow, can we buy leaded gas again? I'll have to get rid of the cat but it'll be worth it.  ::)
Title: Re: Math Question
Post by: maxtog on July 17, 2017, 06:43:59 pm
wow, can we buy leaded gas again? I'll have to get rid of the cat but it'll be worth it.  ::)

Never, ever, get rid of the cat!
Title: Re: Math Question
Post by: B.D.F. on July 17, 2017, 06:51:49 pm
Well, not really a valid question.

If you 'hover over a fixed spot', you would have to put in whatever corrections were needed to maintain that position and so the spot could not move away..... so to speak.

If you simply moved vertically, without any side- motion compensation, you would drift away rapidly but not due to the Coriolis effect but rather because of wind. Think hot air balloon: as soon as they break the tether they drift off.

Maybe the easier way to think of it would be if one were returning to the surface from a great altitude, maybe from orbit for example. If all things were correct and a path plotted that would put the object in a specific point when it landed, and the it was 'let go' and not directed in any way and did indeed follow the path predicted..... it would miss because the target would be in a different place than it was when the device was sent (let go) in the first place.

Not really much of a problem in daily life but hey, now that you know all this stuff, you can try to explain to your wife that there is a "Highly active Coriolis effect Zone" around your toilet and YOU are not REALLY missing, the toilet is not where it was when you.... well, you know. Which is what I suspect was happening at this poor woman's house: http://www.dailymail.co.uk/femail/article-4586394/Mother-leaves-notes-toilet-help-sons-aim.html (http://www.dailymail.co.uk/femail/article-4586394/Mother-leaves-notes-toilet-help-sons-aim.html)

Brian

So if I could hover in the air over a fixed spot for a few days, does that mean that spot will eventually move away from me?
Title: Re: Math Question
Post by: Cholla on July 18, 2017, 10:08:23 am
Absolutely, and you always could. Stop by the local airport and pick up some 100 octane LL AvGas. The LL stands for Low Lead but do not let that fool you- there is a lot of lead in the stuff, just like in the olden' days. Get all you want, bring money.

Brian
Aerodromes arent supposed to sell avgas for road use.
You can go to the local race shop and buy leaded gas in cans or if they have a pump fillerup.
Title: Re: Math Question
Post by: tweeter55 on July 18, 2017, 12:01:02 pm
Well, not really a valid question.

If you 'hover over a fixed spot', you would have to put in whatever corrections were needed to maintain that position and so the spot could not move away..... so to speak.

If you simply moved vertically, without any side- motion compensation, you would drift away rapidly but not due to the Coriolis effect but rather because of wind. Think hot air balloon: as soon as they break the tether they drift off.

Maybe the easier way to think of it would be if one were returning to the surface from a great altitude, maybe from orbit for example. If all things were correct and a path plotted that would put the object in a specific point when it landed, and the it was 'let go' and not directed in any way and did indeed follow the path predicted..... it would miss because the target would be in a different place than it was when the device was sent (let go) in the first place.

Brian

When a rocket takes off and does not  go straight up,  would that be the same thing?
Title: Re: Math Question
Post by: jimmymac on July 18, 2017, 01:31:53 pm
You guys are ate the frick up,man... I need an aspirin.
Title: Re: Math Question
Post by: B.D.F. on July 18, 2017, 02:41:29 pm
No.

This is a simple concept but I am finding it difficult to put into words. I think the problem is that it is not intuitive; we cannot normally see the Coriolis effect and any attempt to simulate it using optics or mechanical means fails.

Let's try this for an example: Say there are two lighthouses, one mile apart. And to make it easier, they are on a line of longitude, meaning one is directly north of the other, no east / west difference at all. And one of them is located at the equator and the other one is one- mile away from the equator, on a perfect north / south line.

Now, you are at the top of the southern lighthouse and you train a telescope on the north lighthouse and measure the angle of the telescope (relative to the Earth's axis, or the North Pole) and find it to be zero (of course). If the telescope is not moved, it will point north and look at a specific spot on the other lighthouse forever.

Then we set up a rifle next to the telescope and also point it perfectly, absolutely north. It is sighted directly on the other lighthouse, in a very  specific point. We will ignore vertical drop in this example to make it simple but again, the rifle is pointed directly at the other lighthouse, as is the telescope next to the rifle. We put a mark on the north lighthouse exactly where the rifle is aimed.

In this example, there is no wind, there is no inaccuracy in the rifle and the projectile will follow a path absolutely straight left / right path, due north, on a line that intersects the north lighthouse where we have marked that lighthouse.

We fire the rifle and wait for the projectile to impact the other lighthouse, directly in- line with the mark placed there. There will be some drop of course but the projectile WILL hit the lighthouse some distance exactly below our previously marked point. It cannot do otherwise. There are no tricks or gimmicks or hidden wrinkles in this example.

But the bullet impacts the north lighthouse SOME DISTANCE to the SIDE of the mark by some inches or feet. We check the rifle, and it is still pointed directly at the mark on the other lighthouse so in our confusion, we fire it again. And again it misses our mark but it impacts in exactly the same point the previous projectile did.

Now, just to make absolutely sure there is nothing wrong here, we now string a cable between the two lighthouses, exactly on the line between the rifle and the point on the other lighthouse that the rifle is aimed toward. The cable is pulled tight and we can verify that the two points on the two lighthouses are indeed directly in- line as shown by the cable (we do not care about any vertical sag in the cable, only the left- right relationship) and perfetly aligned north / south as we knew they had to be.

So the cable is straight. The rifle sends the projectile directly toward a point on the other lighthouse and it travels straight. But the impact point is off to one side, every-time it is tested.

The difference between the impact points and the line- of- sight of the rifle is due to the Coriolis effect. It appears that both lighthouses are fixed and not moving but that is incorrect they are indeed moving, because they are rotating around the axis of the Earth at ~1,000 MPH. The key to this is the fact that both lighthouses (as well as the telescope, the rifle, you and everything else in sight) is fixed to the Earth and being pushed sideways at 1,000 MPH. Because EVERYTHING around you is also moving at this same speed, the movement is not apparent but it is this sideways motion, or rotation, that causes the sun to appear and disappear each day. But in our example, the instant the projectile leaves the barrel, it is NO LONGER being pushed sideways but is now free to travel in a truly straight path, which it does. And when it arrives one mile north, the northern lighthouse has MOVED SIDEWAYS since the projectile was fired and so it misses the point of aim by a substantial amount.

The amount of side movement is dependent on the time it takes the projectile to travel from one lighthouse to the other.

The Coriolis effect is only applicable when an object is sent on a path that will lead toward an object on the Earth's surface but not attached to the Earth's surface. It is a pretty simple math problem to figure out the deceleration rate of the projectile (it starts off moving 1,000 MPH sideways but begins to slow when it leaves the barrel), and the calculate the flight time to yield a specific distance.

And again, per the Paris gun, given the projectile's flight time of three minutes, the 'target' rotated away from the point of aim by almost exactly one kilometer.

Now that is the simplest example. The next thing is to think that this effect reduces as the angle changes toward one more in- line with the equator until it is no longer applicable but because a projectile will always travel in a arc, and the projectile must be launched at some upward angle to hit a distant target, the Coriolis effect still 'bites' the shooter, but instead of a left / right error, we now get a closer / farther error where the projectile lands in front of or behind the point where the arc (called a ballistic path in our case and not a true arc but close enough for this example) would have it land. Again, this if fairly simple to calculate. Of course in the real world, it is almost certain a firearm, an artillery piece, a rocket, a golf ball sent a long way or any other example would ever be on a perfect north / south or east / west line so both parts of the Coriolis effect must be calculated and then added together to get the left / right and too short / too far corrections in the launch azimuth and attitude (the angle of the gun, in rotation around in a circle and the angle the barrel is elevated to before firing).

That is the simplest example I can think of.

'Everything should be made as simple as possible, but not simpler.'
-an axiom attributed to A. Einstein   

What he meant by this is to reduce everything down to the simplest possible explanation or example but not so much that the example or explanation becomes wrong. In my example above, the temptation is to simply say that one seemingly fixed object moves in relationship to another seemingly fixed object but that is too simple and incorrect. So in my view, the simplest explanation is that both objects attached to the Earth are being moved sideways all of the time, and the projectile is NOT being moved sideways for the duration of its flight. That is as simple as I believe it can be made and still be correct and not some bad or wrong example.

The Coriolis effect is also why water swirls in a bowl as it drains out the hole in the bottom (round sink, toilets and so forth), and while the reason is absolutely identical to the above example, the explanation is more complex. So that can be an optional, no added cost, homework assignment.     ;D

The rocket traveling straight up is not sufficient to show the Coriolis effect but if the rocket did have sufficient power or fuel to leave the Earth's gravitation and fell straight back down (straight up, stopped, then straight back down) it would NOT hit the point from which it was launched. That would be an example of the Coriolis effect.

Next weeks' class will be on the Doppler shift (or Doppler effect.... to maintain a steady course curriculum) and how it is used to tell if a distant star is moving toward us, away from us or neither. And if it is moving toward or away from us, exactly how fast. That is a much longer, more detailed and more complex thing than the Coriolis effect is though.

And still on- topic: math answers.  :rotflmao:

Brian

When a rocket takes off and does not  go straight up,  would that be the same thing?
Title: Re: Math Question
Post by: VirginiaJim on July 18, 2017, 03:14:52 pm
You guys are ate the frick up,man... I need an aspirin.

Screw that, I'm going to start drinking.  My brane is hurting.
Title: Re: Math Question
Post by: maxtog on July 18, 2017, 03:51:57 pm
https://www.youtube.com/watch?v=bFEoMO0pc7k (https://www.youtube.com/watch?v=bFEoMO0pc7k)
Title: Re: Math Question
Post by: jimmymac on July 19, 2017, 07:51:03 am
https://www.youtube.com/watch?v=bFEoMO0pc7k (https://www.youtube.com/watch?v=bFEoMO0pc7k)
That was awesome! LOL!
Title: Re: Math Question
Post by: Classvino on July 19, 2017, 10:20:27 am
This is a simple concept but I am finding it difficult to put into words. I think the problem is that it is not intuitive; we cannot normally see the Coriolis effect and any attempt to simulate it using optics or mechanical means fails. ...
Brian

A hypothetical question  ( since you seem to be waxing professorial...)

Since the distance from the equator also affects the speed that everything is moving sideways - imagine a bicycle wheel - an item 1 inch from the centre point and an item 15 inches away from the center move at exactly the same RPM, but the item 1 inch from the centre travels 6.28 inches in one rotation, while the object 15 inches from the centre travels 47.12 inches in one rotation...

So - using your lighthouse example - the distance that the bullet landed from the aim point would be different when one was shooting north, rather than south, given identical conditions - since the south lighthouse would have been travelling faster than the northern one - since the southern lighthouse's 'latitude' would be further away from the earth's axis (assuming northern hemisphere) - right?  (may have to extend the distance to be more easily measured)

Jamie
Title: Re: Math Question
Post by: tweeter55 on July 19, 2017, 11:40:58 am
A hypothetical question  ( since you seem to be waxing professorial...)

Since the distance from the equator also affects the speed that everything is moving sideways - imagine a bicycle wheel - an item 1 inch from the centre point and an item 15 inches away from the center move at exactly the same RPM, but the item 1 inch from the centre travels 6.28 inches in one rotation, while the object 15 inches from the centre travels 47.12 inches in one rotation...

So - using your lighthouse example - the distance that the bullet landed from the aim point would be different when one was shooting north, rather than south, given identical conditions - since the south lighthouse would have been travelling faster than the northern one - since the southern lighthouse's 'latitude' would be further away from the earth's axis (assuming northern hemisphere) - right?  (may have to extend the distance to be more easily measured)

Jamie

Now MY brain hurts!!!
Title: Re: Math Question
Post by: maxtog on July 19, 2017, 03:43:05 pm
That was awesome! LOL!

Hadn't you seen that before?  Was all over the place forever.  Besides being extremely silly/crazy, the autotune music video of the news report was just incredibly well done.  Kinda catchy too.

If you like that one, there is the other one from the same news report:  https://www.youtube.com/watch?v=hMtZfW2z9dw (https://www.youtube.com/watch?v=hMtZfW2z9dw)

"only" 136 MILLION views :)

Title: Re: Math Question
Post by: B.D.F. on July 19, 2017, 03:54:17 pm
Yeah, I understand it appears that way (professorial) and it may be exactly what it is; I find this 'junk' fascinating and tend to enjoy both learning it as well as trying to find examples that are (believe it or not) as simple and direct as possible.

And yep, what you say is exactly what would happen because one lighthouse is moving faster than the other. To alter that example so that it would not matter which way the projectile traveled, the lighthouses would have to be the same distance away from and on either side of the equator; one 1/2 mile north of the equator and the other 1/2 mile south, to maintain the same spacing between them and yet have the same rotational speed. I did not bother with that complication because I really was shooting (pun marginally intended, I cannot find an place to put an Easy Boys! anywhere in this thread..... yet) for the simplest example I could think of.

Brian

A hypothetical question  ( since you seem to be waxing professorial...)

Since the distance from the equator also affects the speed that everything is moving sideways - imagine a bicycle wheel - an item 1 inch from the centre point and an item 15 inches away from the center move at exactly the same RPM, but the item 1 inch from the centre travels 6.28 inches in one rotation, while the object 15 inches from the centre travels 47.12 inches in one rotation...

So - using your lighthouse example - the distance that the bullet landed from the aim point would be different when one was shooting north, rather than south, given identical conditions - since the south lighthouse would have been travelling faster than the northern one - since the southern lighthouse's 'latitude' would be further away from the earth's axis (assuming northern hemisphere) - right?  (may have to extend the distance to be more easily measured)

Jamie
Title: Re: Math Question
Post by: B.D.F. on July 19, 2017, 04:03:10 pm
That is how I feel one page into anything written by Shakespeare. Or poetry. And the great novels.

I like things with repeatable, physical 'rules' but seem immune to kultur.

With a couple of exceptions: Henry V was pretty good IMO and I think the only one of the very few plays of Shakespeare I have read (forced to do so) that I liked, probably because 1) I saw it as a study of human tenacity and I love tenacity, and 2) 'cause the English took France. What English speaker, anywhere in the world, does not like that?

 :rotflmao:

Brian

Now MY brain hurts!!!
Title: Re: Math Question
Post by: Rhino on July 20, 2017, 06:24:32 am
Had insomnia last night. Started thinking of the coriolis effect. I believe it is entirely due to the difference in angular movement between 2 points. Shooting directly east or west there is no difference. I do not believe it will make any difference which direction (east or west) as to weather or not the shot will be long or short. Same is true shooting north and south across the equator to a point equal distance from the equator. But lets consider the Paris gun shooting 100 miles to a target directly on the north pole. The target will be stationary. But the gun will be moving along a circle ~628 miles in circumference (100*2*pi) at the rate of 1 revolution per day. That is about 26 mph to the right (left if south pole) from the perspective of the gun looking at the target. If the projectile flight time is 3 minutes that would be ~1.3 miles. The gunner would have to aim at a point 1.3 miles to the left of the target.

Now we know the equation to compensate for Coriolis effect for the Paris gun. Paris is on the 48.8 parallel. cos(latitude)*(radius of earth)*2*pi per day is the angular speed of Paris. ( cos(48.8 )*4000*2*3.14 )/24 = About 690 mph. A point 100 miles south of Paris is about 1 degree south and moving at about 703 mph. A difference of 13 mph. 3 min flight time would be a difference of about .65 miles. Very close to what you said about being off by 1/2 mile. But I'm sure the gun was not in Saint-Benoît-sur-Loire. Apply these equations to any 2 points 100 miles apart on or near the equator and the difference is negligible.

That's my math and I'm sticking to it!
Title: Re: Math Question
Post by: gPink on July 20, 2017, 06:33:31 am
Are you talking actual north or magnetic north?
Title: Re: Math Question
Post by: Rhino on July 20, 2017, 06:39:02 am
Are you talking actual north or magnetic north?

For Coriolis effect the magnetic pole does not matter. True north is what matters.
Title: Re: Math Question
Post by: B.D.F. on July 20, 2017, 07:08:33 am
Sorry to hear about the insomnia.

The Coriolis effect is not due to the difference in rotational (or angular) velocities on different points on Earth, it is due entirely to the projectile slowing down only in relationship to the Earth's rotation, and the flight time to first point of impact (POI). Again, the only thing that can cause the projectile to strike anyplace other than where it was expected to strike is that the projectile itself is no longer connected to the two points, launch and impact. The cable example shows this I believe: if the cable is straight, and the projectile path is straight, what is happening that is causing the projectile to deviate from the cable's line.

If the projectile trajectory is on a line of latitude, with the equator being the line that would have the greatest effect, the Coriolis effect is far more noticable because it is no longer dependent only on the projectile's deceleration.

A quick search turned up this:https://loadoutroom.com/thearmsguide/external-ballistics-the-coriolis-effect-6-theory-section/

And from this site, I quote: "Despite being associated with Coriolis, the phenomenon that actually affects the vertical component of the trajectory is called Eötvös Effect. The rotation of the Earth generates a centrifugal force, the same that pushes you to the side when you make a sharp turn with your car. This force acts perpendicular to the Earth rotatory axis, adding or subtracting to the gravity force. When an object flies eastward, in the same direction of Earth’s rotation, centrifugal force acts opposite of gravity, pushing it away from the Earth’s surface. If the object flies westward, in the opposite direction of the Earth rotation, centrifugal force pushes the object toward the ground concurrently to gravity force. Thus, bullets fired to the east always fly a little higher, and, conversely, bullets fired to the west always travel somewhat low.

The amount of drop change is in function of:

Latitude – The linear velocity of a point on the Earth’s surface, and thus the amount of centrifugal force, is maximum at the equator and decreases going toward the poles, where it is null.

Shooting direction, or azimuth – The amount of drop change is highest when shooting east or west, and as the trajectory angles north or south,  the amount of drop change decreases, becoming null, as the angle points toward either pole. "

The key here is that this site has actually disassembled the two components of the Coriolis effect into the north / south component, properly called the Eötvös Effect, and the simpler, direct component of the Coriolis effect, which is what occurs on a line of latitude (east / west direction).

Again, there is no direction which this effect does not apply to: purely east / west, the point of impact is either moving toward or away from the point of launch.

A simple drawing showing the effect's results using a north / south trajectory: http://www.dictionary.com/browse/coriolis-effect (http://www.dictionary.com/browse/coriolis-effect)

Brian

Had insomnia last night. Started thinking of the coriolis effect. I believe it is entirely due to the difference in angular movement between 2 points. Shooting directly east or west there is no difference. I do not believe it will make any difference which direction (east or west) as to weather or not the shot will be long or short. Same is true shooting north and south across the equator to a point equal distance from the equator. But lets consider the Paris gun shooting 100 miles to a target directly on the north pole. The target will be stationary. But the gun will be moving along a circle ~628 miles in circumference (100*2*pi) at the rate of 1 revolution per day. That is about 26 mph to the right (left if south pole) from the perspective of the gun looking at the target. If the projectile flight time is 3 minutes that would be ~1.3 miles. The gunner would have to aim at a point 1.3 miles to the left of the target.

Now we know the equation to compensate for Coriolis effect for the Paris gun. Paris is on the 48.8 parallel. cos(latitude)*(radius of earth)*2*pi per day is the angular speed of Paris. cos(48.8)*4000*2*3.14 = About 690 mph. A point 100 miles south of Paris is about 1 degree south and moving at about 703 mph. A difference of 13 mph. 3 min flight time would be a difference of about .65 miles. Very close to what you said about being off by 1/2 mile. But I'm sure the gun was not in Saint-Benoît-sur-Loire. Apply these equations to any 2 points 100 miles apart on or near the equator and the difference is negligible.

That's my math and I'm sticking to it!
Title: Re: Math Question
Post by: B.D.F. on July 20, 2017, 07:10:54 am
True north, the actual lines of longitude that run from the north to the south poles.

Magnetic north is not a physical reality, merely a 'cheap parlor trick' we humans use with our crude efforts to navigate with a compass.

Brian

Are you talking actual north or magnetic north?
Title: Re: Math Question
Post by: jimmymac on July 20, 2017, 07:24:51 am
Hadn't you seen that before?  Was all over the place forever.  Besides being extremely silly/crazy, the autotune music video of the news report was just incredibly well done.  Kinda catchy too.

If you like that one, there is the other one from the same news report:  https://www.youtube.com/watch?v=hMtZfW2z9dw (https://www.youtube.com/watch?v=hMtZfW2z9dw)

"only" 136 MILLION views :)
I have no idea how I missed it... I did catch the original interview though... Great stuff, Max.
Title: Re: Math Question
Post by: Rhino on July 20, 2017, 11:22:14 am
Interesting. I will have to study the Eötvös Effect more. This is why NASA launches to the east the vast majority of the time. Extra 1000 mph is a lot of rocket fuel.

But I still maintain that the Coriolis Effect is near zero at the equator and more pronounced at the poles due the the difference in the rate of angular movement. I did find a website that agrees with me:

https://www.quora.com/Why-is-the-Coriolis-force-zero-at-the-equator-and-maximum-at-the-poles (https://www.quora.com/Why-is-the-Coriolis-force-zero-at-the-equator-and-maximum-at-the-poles)

The Coriolis force acts in a direction perpendicular to the rotation axis and to the velocity of the body in the rotating frame and is proportional to the object's speed in the rotating frame.
The Coriolis effect is caused by the rotation of the Earth and the inertia of the mass experiencing the effect. Because the Earth completes only one rotation per day, the Coriolis force is quite small, and its effects generally become noticeable only for motions occurring over large distances and long periods of time, such as large-scale movement of air in the atmosphere or water in the ocean. Such motions are constrained by the surface of the earth, so only the horizontal component of the Coriolis force is generally important.
 The horizontal deflection effect is greater near the poles and smallest at the equator, since the rate of change in the diameter of the circles of latitude when travelling north or south, increases the closer the object is to the poles.

Hey! My insomnia fueled brain farts can't be wrong!


Sorry to hear about the insomnia.

The Coriolis effect is not due to the difference in rotational (or angular) velocities on different points on Earth, it is due entirely to the projectile slowing down only in relationship to the Earth's rotation, and the flight time to first point of impact (POI). Again, the only thing that can cause the projectile to strike anyplace other than where it was expected to strike is that the projectile itself is no longer connected to the two points, launch and impact. The cable example shows this I believe: if the cable is straight, and the projectile path is straight, what is happening that is causing the projectile to deviate from the cable's line.

If the projectile trajectory is on a line of latitude, with the equator being the line that would have the greatest effect, the Coriolis effect is far more noticable because it is no longer dependent only on the projectile's deceleration.

A quick search turned up this:https://loadoutroom.com/thearmsguide/external-ballistics-the-coriolis-effect-6-theory-section/

And from this site, I quote: "Despite being associated with Coriolis, the phenomenon that actually affects the vertical component of the trajectory is called Eötvös Effect. The rotation of the Earth generates a centrifugal force, the same that pushes you to the side when you make a sharp turn with your car. This force acts perpendicular to the Earth rotatory axis, adding or subtracting to the gravity force. When an object flies eastward, in the same direction of Earth’s rotation, centrifugal force acts opposite of gravity, pushing it away from the Earth’s surface. If the object flies westward, in the opposite direction of the Earth rotation, centrifugal force pushes the object toward the ground concurrently to gravity force. Thus, bullets fired to the east always fly a little higher, and, conversely, bullets fired to the west always travel somewhat low.

The amount of drop change is in function of:

Latitude – The linear velocity of a point on the Earth’s surface, and thus the amount of centrifugal force, is maximum at the equator and decreases going toward the poles, where it is null.

Shooting direction, or azimuth – The amount of drop change is highest when shooting east or west, and as the trajectory angles north or south,  the amount of drop change decreases, becoming null, as the angle points toward either pole. "

The key here is that this site has actually disassembled the two components of the Coriolis effect into the north / south component, properly called the Eötvös Effect, and the simpler, direct component of the Coriolis effect, which is what occurs on a line of latitude (east / west direction).

Again, there is no direction which this effect does not apply to: purely east / west, the point of impact is either moving toward or away from the point of launch.

A simple drawing showing the effect's results using a north / south trajectory: [url]http://www.dictionary.com/browse/coriolis-effect[/url] ([url]http://www.dictionary.com/browse/coriolis-effect[/url])

Brian
Title: Re: Math Question
Post by: Tree on July 20, 2017, 11:34:30 am
Right. And maybe even more importantly, he may not have been where he thought he was when he filled up his fuel tank in the first place.

The plot thickens....

Brian

I totally confused Coriolis with Vortex.  Would it have made a difference if I were travelling in a north/south direction?  On the other hand, it doesn't matter because it has nothing to do with coconuts.
Title: Re: Math Question
Post by: VirginiaJim on July 20, 2017, 12:11:07 pm
Ok, you said coconuts...

http://youtu.be/Z47NljuPBFE (http://youtu.be/Z47NljuPBFE)
Title: Re: Math Question
Post by: Tree on July 20, 2017, 12:22:59 pm
Ok, you said coconuts...

[url]http://youtu.be/Z47NljuPBFE[/url] ([url]http://youtu.be/Z47NljuPBFE[/url])


Yes, Yes I Did.

! No longer available (http://www.youtube.com/watch?v=JHFXG3r_0B8#)
Title: Re: Math Question
Post by: VirginiaJim on July 20, 2017, 12:49:20 pm
Yes, that one came to mind as well...excellent choice.  By the way, when you post in a YouTube vid, before you save the post, remove the s on https.   That way the vid will show up instead of just the link.
Title: Re: Math Question
Post by: B.D.F. on July 20, 2017, 01:43:41 pm
Post altered 21 July by BDF to remove my initial reply to Rhino, which I now think was wrong. See next post for why I now think Rhino was right.

Brian

Interesting. I will have to study the Eötvös Effect more. This is why NASA launches to the east the vast majority of the time. Extra 1000 mph is a lot of rocket fuel.

But I still maintain that the Coriolis Effect is near zero at the equator and more pronounced at the poles due the the difference in the rate of angular movement. I did find a website that agrees with me:

https://www.quora.com/Why-is-the-Coriolis-force-zero-at-the-equator-and-maximum-at-the-poles (https://www.quora.com/Why-is-the-Coriolis-force-zero-at-the-equator-and-maximum-at-the-poles)

The Coriolis force acts in a direction perpendicular to the rotation axis and to the velocity of the body in the rotating frame and is proportional to the object's speed in the rotating frame.
The Coriolis effect is caused by the rotation of the Earth and the inertia of the mass experiencing the effect. Because the Earth completes only one rotation per day, the Coriolis force is quite small, and its effects generally become noticeable only for motions occurring over large distances and long periods of time, such as large-scale movement of air in the atmosphere or water in the ocean. Such motions are constrained by the surface of the earth, so only the horizontal component of the Coriolis force is generally important.
 The horizontal deflection effect is greater near the poles and smallest at the equator, since the rate of change in the diameter of the circles of latitude when travelling north or south, increases the closer the object is to the poles.

Hey! My insomnia fueled brain farts can't be wrong!
Title: Re: Math Question
Post by: B.D.F. on July 20, 2017, 05:28:04 pm
So this stuck with me and I kept coming back to it..... and I think you are right and I was wrong (but may be getting 'righter' after shaking off my  earlier, wrong, thinking).

First: launching into orbit, yep, the velocity is a 'freebie' and absolute regarding orbital velocity. I missed it because I was thinking about the entire flight (including landing) but that is irrelevant. All that is required is a fixed amount of acceleration to an altitude and velocity, and starting off going with the Earth's rotation would just add or subtract.

The second part is harder for me to see because I am stuck on the fact that 'force' would be lost at launch. And that is fine and well but does not mean anything if there is nothing trying to alter the projectile's initial velocity in the first place. This is what I think I missed or rather kept injecting but does not belong: there is a velocity added or subtracted, so what? Nothing external will exert any force on the projectile to reduce or increase that velocity! The entire path becomes  So again, I think you are and were right and I was wrong- the Coriolis effect does reduce to zero as the angle approaches and reaches a direction parallel with the Earth's rotation, any line of latitude. This only applies at the equator but that is what we have been talking about.

Moving away from the equator makes it more complex because I do not think there are any 'straight' lines of latitude anymore that will not cross a curve. Still thinking about that one though.

So thanks for the input and correction- it is always best to be correct as much as can be. Your insomnia turned into my.... afternoonstuckinthethought onmia.  ;) ;D

I did go looking for calculating 'accessories', formulas, a spreadsheet or similar but everything I found is commercial and has to be purchased. So much for the easy way out of 'plug 'n chug' calculating. Going to have to do this the hard way and work with the rules and physics.

Thanks again!

Brian

Interesting. I will have to study the Eötvös Effect more. This is why NASA launches to the east the vast majority of the time. Extra 1000 mph is a lot of rocket fuel.

But I still maintain that the Coriolis Effect is near zero at the equator and more pronounced at the poles due the the difference in the rate of angular movement. I did find a website that agrees with me:

https://www.quora.com/Why-is-the-Coriolis-force-zero-at-the-equator-and-maximum-at-the-poles (https://www.quora.com/Why-is-the-Coriolis-force-zero-at-the-equator-and-maximum-at-the-poles)

The Coriolis force acts in a direction perpendicular to the rotation axis and to the velocity of the body in the rotating frame and is proportional to the object's speed in the rotating frame.
The Coriolis effect is caused by the rotation of the Earth and the inertia of the mass experiencing the effect. Because the Earth completes only one rotation per day, the Coriolis force is quite small, and its effects generally become noticeable only for motions occurring over large distances and long periods of time, such as large-scale movement of air in the atmosphere or water in the ocean. Such motions are constrained by the surface of the earth, so only the horizontal component of the Coriolis force is generally important.
 The horizontal deflection effect is greater near the poles and smallest at the equator, since the rate of change in the diameter of the circles of latitude when travelling north or south, increases the closer the object is to the poles.

Hey! My insomnia fueled brain farts can't be wrong!
Title: Re: Math Question
Post by: Rhino on July 21, 2017, 08:01:57 am
Hey Brian, more insomnia last night (I don't think I'm getting enough alcohol). Thought some more about the Eötvös effect last night and how much it would actually effect ballistics of a gun like a 1 mile sniper shot. Due to this effect you would weigh more standing at one of the poles then you do at the equator. I googled it this morning and found this NASA response. 0.35%! You weigh 0.35% less at the equator than you do at the north pole. Way more then I would have thought. I don't know the equation to calculate centrifugal force but if I use a linear extrapolation (I realize this may not be a linear function), a 338 Lapua muzzle velocity of about 3000 ft/sec is about 2000 mph. Therefor at the equator a sniper shooting east the bullet will be traveling 3000 mph relative to the center of the earth, but shooting west only 1000 mph. The felt gravitational pull on the bullet will be about 1% different. I don't know how to calculate the ballistics based on this but if we are talking 1 shot 1 kill, you would definitely need to calculate that into the shot. And 1% on a 100 mile shot from the Paris gun could be a mile? If this is the case, then it has as much or more of an effect as the Coriolis effect. I think you were correct in that you need to calculate both effects weather you are at the equator or a pole and everywhere in between. Now I wonder if the Shooter app I have on my iPhone calculates the Eötvös effect as well as the Coriolis effect (not that it really matters when I'm at the trigger, my skills do not come close to having to worry about this).

https://image.gsfc.nasa.gov/poetry/ask/a11511.htm