[Ghoser777]

So a 2D ball collisions question. I know the immediate answer is "do it in component form," but here's my question anyway. Let's say you have two balls (chuckle) that are traveling in space and they collide (lol - he has colliding balls). I know both of their velocities in component form. The masses of the bodies are not really specified (this is for a program I'm going to have my class write), although the mass of one ball should greatly outweigh the mass of another (imagine volleyball versus volleyball player). My initial idea was to go with conservation of kinetic energy and linear momentum (which seem easy enough)... but there is one thing this seems to leave out - what if the angle of intersection is not the same as the angle of motion?

For example, say you have one ball moving horizontally to the right at 1,000,000 mi/hr and a second ball that is falling downward and to the left and 10 mi/hr. If the second ball hits the first ball at a 90˚ angle (essentially dead center on top), none of the first ball's momentum is transfered, right? Won't the second ball simply bounce off an go on it's merry way?

Second example - let's say the same thing happens but now the second ball intersects the first ball at 0˚ (essentially dead to the right of it) - won't there be maximal transfer of momentum?

So what I was wondering is if I need to do something with the components along the angle of intersection. Any physics people talked a problem like this before?

[scaught]

3. The answer is 3.

[Railroader]

As much as I wish I could help you, here is a video of balls colliding that will make you squirm if you are a man.

YouTube - FSN Sport Science - Episode 4 - Cheap Shots - Crotch Test 2

[Ghoser777]

Eureka!

2D Collision

[Railroader]

This one is good too: Collision 2D

[alligator]

It really depends on mass. In your first example, a small amount of force will be applied in a downward direction and the fast moving ball will deflect slightly downward. In the second example, the small ball will certainly experience an increase in momentum toward the right, but again, it depends on the mass of both balls. We know that momentum is conserved in a closed system, so there can't be a net increase overall. I'm too lazy to break it down into coordinates, but yes, that's the way I'd do it.

To solve this, you'd use F=ma, and p=mv. Both depend on mass.

If you want to experiment online with a flash simulation, I suggest you try this site.

[tie]

Your own post has the answer. Use conservation of energy and conservation of momentum in each direction. Note that the impulse at the collision goes from one center to the other. The solution is then unique.

[Buckaroo]

Damn, that guy must be one of those guys that like women with stalletos standing on their thing.

Originally Posted by Railroader 

As much as I wish I could help you, here is a video of balls colliding that will make you squirm if you are a man.

YouTube - FSN Sport Science - Episode 4 - Cheap Shots - Crotch Test 2

[SVass]

According to Douglas Adams, the answer is 42.
According the Dr. Ken Nordtvedt, the one moving at high speed drags the "frame" along. "Using the distance measurements, Nordtvedt's team calculated the strength of the so-called gravitomagnetic field. Gravitomagnetism is a relativistic addition to the ordinary Newtonian version of gravity, which doesn't take the motions of bodies into account. It's the gravitomagnetic field that causes frame dragging, Nordtvedt says. "

sam

[ShortcutToMoncton]

Originally Posted by Railroader 

As much as I wish I could help you, here is a video of balls colliding that will make you squirm if you are a man.

That dude is hilariously bowlegged.

greg