Conservation of Momentum for Inelastic Collisions

[david888lee]

Okay here goes...

I'm having a hard time trying to logically understand how momentum is conserved for inelastic collisions, even though energy is lost. Since energy is lost (in the form of kinetic energy) how can the initial momentum be the same as final momentum. I know I may be confusing conservation of momentum with conservation of mechanical energy but can someone explain this in a simple example to help me visualize it? Thanks in advance!

David

 

[Bob_for_short]

Okay here goes...

I'm having a hard time trying to logically understand how momentum is conserved for inelastic collisions, even though energy is lost. Since energy is lost (in the form of kinetic energy) how can the initial momentum be the same as final momentum. I know I may be confusing conservation of momentum with conservation of mechanical energy but can someone explain this in a simple example to help me visualize it? Thanks in advance!

David

Yes, in fact, it is easy. The conservation of momentum is formulated as follows: sum of momenta of all interacting particles conserves for an isolated system whatever internal interaction is.

In inelastic collision some part of initial kinetic energy is spent on rearranging particles within bodies so the total momentum conserves while the kinetic energy does not. Only the sum of kinetic and (new) potential or better other form of energy is conserved. You see, the problem is in fact that kinetic energy is not the sole form of energy in nature, it should not be conserved in general case.