Author Topic: 3 & 4 diabolo in slow motion 3000FPS by Ofek Shilton  (Read 11115 times)

Sean

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Re: 3 & 4 diabolo in slow motion 3000FPS by Ofek Shilton
« Reply #20 on: April 05, 2011, 08:30:21 AM »
can you use this to work out how fast the diabolos are spinning?
Didn't Nate Sharpe do this (among other calculations with a high speed camera and a strobe light)? If I remember correctly, it was for a university class. He linked to the file somewhere on the forum.

Edit, found it: http://diabolo.ca/forum/index.php?topic=5902
However, the images are dead and the MIT url to the pdf is dead too. Ah, the internet.

Nice video by the way. Thanks for sharing that. You're looking older every time I see you. Making me feel old!

Jussi

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Re: 3 & 4 diabolo in slow motion 3000FPS by Ofek Shilton
« Reply #21 on: April 05, 2011, 09:21:00 AM »
I was asking whether you could use this camera to work out the speed of the diabolo, not just this video.

Of course you can? Why not. Just count rotations if you know slowing rate. As toby said.

Its quite easy to measure and calculate diabolo's moment of inertia - i write an article about it to finnish diabolo assosiation newsletter.
http://koti.kapsi.fi/~hel5am/sds/wp-content/uploads/2011/04/sdsnews7.pdf (page 2-4 its finnish, but you will understand at least results anyhow) When you know speed (angular velocity) of diabolo and moment of inertia, you can calculate rotational kinetic energy of diabolo.

I have nate sharpe's paper somewhere, but he only measured how big angular velocities you can get with different acceleration methods - i think it would be more interesting to study about energy conversion effiency with different acceleration methods and with different diabolo models!

There is lot of very elementary things that we dont know .. like "when you throw diabolo high and take it to string, how big part of diabolos highest state potential energy is possibly to convert to rotational kinetic energy" - wery interesting, dont you think?

Crackers

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Re: 3 & 4 diabolo in slow motion 3000FPS by Ofek Shilton
« Reply #22 on: April 08, 2011, 05:05:28 PM »
Lucky you!
Out of curiosity, how did you get access to that kind of gear?

 

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