In a center-of-mass reference frame for a system with no external forces applied to it,
A) the system's kinetic energy is zero.
B) momentum is not conserved.
C) the total momentum is zero.
D) all collisions are elastic.
E) None of these is correct.

Question

Quizplus · Accepted Answer

In a center-of-mass reference frame, the total momentum of the system is zero by definition, since the velocity of the center of mass is zero in this frame. The other statements are not necessarily true in this frame; the kinetic energy can still be non-zero, momentum is conserved in all frames regardless of external forces, and the collisions can be either elastic or inelastic.

In a Center-Of-Mass Reference Frame for a System with No