if momentum is conserved in an inelastic collision is it possible to get zero kinetic energy in such collision

Question

consider linear inelastic collision, we know:
momentum = mass x Velocity
Kinetic energy = 0.5 x mass x Velocity ^2
both directly proportional to velocity...if there is no loss in mass, velocity is the only way to reduce kinetic energy due to the inelastic collision.how can momentum remain the same yet kinetic energy gets reduced ( for the system of two colliding solids).
one case that comes to mind:
we bounce a golf ball between two walls in a room in space (vaccum inside and zero gravity). if Kinetic energy gets lost due to the inelastic collision then the velocity will eventully be 0 and the ball will stop...which means the momentum of the ball will be zero.the room istelf will have to be at rest since the bouncing between the two walls should cancel out given the momentum conservation laws...something is wrong in this picture I am just not sure what it is?
any advice is more than welcome.
thanks

Answer 1

First let get some definition for inelastic collision:
“Inelastic collision is a collision in which some of the kinetic energy of the colliding bodies is converted into internal energy in at least one body such that kinetic energy is not conserved. “ http://en.wikipedia.org/wiki/Inelastic_collision

So where does this kinetic energy goes? From macro world to micro world, that is the kinetic energy of the bodies will partially increase the kinetic energy of the atoms of these bodies and the bodies would heat up.

Kinetic energy before = kinetic energy after
K1b + K2b +k1b + k2b= K1a + K2a +k1a + k2a
K = (mv^2)/2
k = thermal energy of the body (to total kinetic energy of atoms)

Ahh I almost forgot – The momentum, the momentum.

The momentum is conserved only part of it tuned into increase momentum of atoms.
Macro world and micro world in this case must go together.

Answer 2

It's the momentum of the *system* that is conserved - in this case the system must be the ball and the walls it is bouncing off of. Remember that momentum also has a direction - when a ball bounces off a wall (be it elastic or partially inelastic) its momentum changes from being positive to being negative, and the wall's momentum also changes. Wallls on Earth are (usually) firmly planted in the ground, and since the Earth is so massive, the velocity of the wall doesn't change much. But imagine doing the same experiment with a ball in a cardboard box - you would notice that the box, originally stationary, begins to move when it's hit from the inside by the ball.

Answer 3

I think the issue is the phrase 'perfectly inelastic'. If the collision is really perfectly inelastic, then all of the velocity will either remain in the impacting body or impacted body, or some combination. But no collision is prefectly inelastic, even the golf ball in space in a vacuum. Some energy is always lost in friction or heat, so every collision has soem energy loss.