PDA

View Full Version : Momentum Question

anubis2003
30th January 2003, 23:38
Here is my question:
If given the initial x and y velocities in a 2-D elastic [glancing] collision between two spherical objects, how can you find the final velocities and directions (components or velocity and direction).
I believe it has something to do with figuring it out in the n-t axes and then rotating to the x-y axes, but I'm not positive.
Any help would be greatly appreciated and I would also like to see the steps required. That way if I try doing it in 3-D I can figure it out myself. Thanks.

dirkdeftly
31st January 2003, 22:36
Another GREAT thing for UnConeD :P He showed the p33pz at #finnish-flash a rather neet physics demonstration that does (if I'm correct) exactly that...

anubis2003
1st February 2003, 00:39
Yeah, I figured if anyone would know it unconed would. I was only able to find 2 websites that seemed to figure out the problem I'm trying to figure out. One was by a princeton professor, and the other was by some physics professor. It is really easy to do this problem if one of the balls is at rest initially or the paths intersect at 90 degrees or 180 degrees(1-D). Any other angles and it is a glancing collision that is very difficult to solve.

UnConeD
1st February 2003, 05:49
Lemme dig up my mechanics book later.

Right now I have 6 hours to go until physics exam (that's 4cm of paper that should be in my head now :(, but it isn't) so I don't have much time.

But I do give myself 5 minutes to pauze and surf the web (and post comments at lightningspeed) :rolleyes:

dirkdeftly
1st February 2003, 06:52
yes, telling from "lightningspeed" and "pauze" :p not to mention how you use don't stop to spell the numbers, which if I'm correct you normally do

anubis2003
5th February 2003, 22:06
YES! I finally figured it out. Here is a small example. I will turn it into a worthy preset soon and repost. Who knows, if I can figure out the 3-D equations it will definitely be awesome. This took me hours to figure out. But it worked!