Question

If no external force is acting on a two body system, what will happen to (a) velocity of centre of mass (b) angular momentum?

Answer 1

In absence of any external force, the center of mass of a two body system will have zero acceleration.

Since, F = ma_cm => 0 = ma_cm => a_cm = 0

So, the center of mass of the system will continue its state of rest or of uniform motion.


Angular momentum = mvr
as velocity is constant , so it will also remain constant.