Collision Reaction: Mass Difference & Speed Exchange

AI Thread Summary
The discussion revolves around the behavior of two colliding balls with different masses and speeds. It highlights that in a completely elastic collision, both momentum and kinetic energy are conserved, while in a completely inelastic collision, only momentum is conserved. The original poster expresses confusion about the effects of mass differences on collision outcomes, relying on intuition rather than formal physics principles. The conversation emphasizes the need for understanding concepts like the coefficient of restitution and conservation of kinetic energy for accurate predictions. Overall, the thread serves as a basic exploration of collision dynamics in physics.
hadari
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Hello,
I have a question about how balls react on collision while having diffrent mass,
lets say two balls are moving on one dimension, the first ball has the speed of V1, mass of M1, and the other ball has V2,M2.
what will be their speed after the collision?
assuming there are no other forces involved.
It is logical to me that if their mass is the same, the balls will exchange their speed, but I don't know what will happen if the balls will be with diffrent mass.
 
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Welcome to PF hadari,

If one assumes that the collision is completely elastic then both momentum and kinetic energy are conserved and the problem can be solved.

If one assumes that the collision is completely inelastic then just momentum is conserved and the problem can be solved.

In the case where neither of the above apply then the problem cannot be solved without further information.
 
Thanks you solved all my problems :)
 
hadari said:
It is logical to me that if their mass is the same, the balls will exchange their speed, but I don't know what will happen if the balls will be with diffrent mass.

I am just curious to know on what you based this conclusion, because you didn't mention anything about the co-eff of restitution or consvn of KE.
 
Last edited:
I didn't mention "co-eff of restitution or consvn of KE" because I don't know what any of those means, I don't know much about physics, I'm a programmer and just wanted to build a physics engine for a project I have. That conclusion was based on intuition only.
 
Hootenanny has replied to you qualitatively, without going into any math. Could you really understand everything about collision of balls from that?

(Please ignore this post if you feel that it is not productive for you to continue with this discussion.)
 

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