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A (relatively) readable paper on ballistics (Read 2146 times)
wanderer
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A (relatively) readable paper on ballistics
Oct 20th, 2016 at 3:32pm
 
While revisiting the whole sorry business of calculating trajectories with air resistance, considering the Burnswark thread, I ran into the following fairly recent paper

http://rspa.royalsocietypublishing.org/content/470/2161/20130497

I didn't think articles from this site are usually freely available, but this one was available at least in U.K.

It deals with the trajectory of projectiles under quadratic drag and is fairly readable, though it does have equations in it Wink. There appear to be some results which are new (at least I wasn't aware of them) as far as calculating some of the optimal parameters.

I think there are at least two or three others here who might find it interesting. Apologies if it has been spotted and posted before - I havn't found any reference to it on this site, but I may have missed any such.
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johan
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Re: A (relatively) readable paper on ballistics
Reply #1 - Oct 21st, 2016 at 5:14am
 
how much further will a stone with backspin go?
most people call it backspin but in the paper it is called topspin.
i liked the +50% range gained by the football just with spin. i didnt know that spin was adding that much range.

check this: http://slinging.org/forum/YaBB.pl?num=1457457030/4#4

we have made similar conclusions about optimal angle
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Curious Aardvark
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Re: A (relatively) readable paper on ballistics
Reply #2 - Oct 21st, 2016 at 11:39am
 
surely topspin in a sphere is rotating away from you. while back spin is rotating towards you.
Topspin will make a ball dive, backspin will make it rise.
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Bill Skinner
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Re: A (relatively) readable paper on ballistics
Reply #3 - Oct 21st, 2016 at 4:54pm
 
C_A, there you go adding practical experience to a theoretical discussion.
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wanderer
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Re: A (relatively) readable paper on ballistics
Reply #4 - Oct 22nd, 2016 at 1:16am
 
Parmenion, as far as I can see the paper seems to use 'topspin' in the way C_A, I and I think most people understand it. Their figures give shorter ranges with topspin than with no, or backspin which is as it should be. Did they mistakenly use it the other way around in the text somewhere?

The predictions for increased distance with backspin seem about right. I think the trouble is always figuring out how rapidly the ball is actually spinning.

Bill, it's not just a theory paper. They stuck various sports balls in a vertical wind tunnel and measured terminal velocities directly.
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Re: A (relatively) readable paper on ballistics
Reply #5 - Oct 22nd, 2016 at 5:51am
 
Bill Skinner wrote on Oct 21st, 2016 at 4:54pm:
C_A, there you go adding practical experience to a theoretical discussion.


lol I know, it's a habit I just can't seem to shake Smiley
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johan
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Re: A (relatively) readable paper on ballistics
Reply #6 - Oct 22nd, 2016 at 10:46am
 
wanderer wrote on Oct 22nd, 2016 at 1:16am:
Parmenion, as far as I can see the paper seems to use 'topspin' in the way C_A, I and I think most people understand it.



lol you are right i'm seeing things Tongue
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