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.

 

[astrokreng]

,

I completely understand your confusion about the conservation of momentum for inelastic collisions. It can be a difficult concept to grasp at first, but I'll try to explain it as simply as possible.

First of all, let's define what an inelastic collision is. In simple terms, it is a collision where the objects involved stick together after the collision and move as one mass. This is different from an elastic collision where the objects bounce off each other with no loss of kinetic energy.

Now, let's use an example to visualize this. Imagine two balls of the same mass, one at rest and the other moving towards it with a certain velocity. When they collide, the first ball will absorb the energy of the second ball and start moving with a velocity that is less than the initial velocity of the second ball. This is because some of the kinetic energy was lost in the collision.

However, the total momentum of the system (both balls together) will remain the same before and after the collision. This is because momentum is calculated by multiplying mass and velocity, and since the mass remains the same, the velocity of the combined mass must also remain the same in order for the momentum to be conserved.

In other words, even though the kinetic energy is lost, the mass of the system is also increased due to the two objects sticking together. This results in a lower velocity for the combined mass, but the same overall momentum as before the collision.

I hope this helps to clarify the concept of conservation of momentum for inelastic collisions. Just remember, momentum is always conserved in any type of collision, but kinetic energy may not be.