Two trolleys collide on a frictionless track. Set their masses and velocities and choose an elastic or a perfectly inelastic collision. Whatever you pick, the total momentum just after the collision equals the total just before, because there is no external resultant force. Kinetic energy, by contrast, is only conserved in the elastic case.
MissionRun a collision, then predict what happens to the total momentum.Streak 0Best 0
In this collision, with no external force, the total momentum just after is:
total momentum before2.0 kg m/s
total momentum after2.0 kg m/s
total kinetic energy before / after- / -
Elastic: both momentum and kinetic energy conserved. Inelastic: momentum conserved, kinetic energy is not.