H C Verma Solutions for Chapter: Centre of Mass, Linear Momentum, Collision, Exercise 3: OBJECTIVE II

If the external forces acting on a system have zero resultant, the centre of mass

A non-zero external force acts on a system of particles. The velocity and the acceleration of the centre of mass are found to be $v_0$ and $a_0$ at an instant $t$. It is possible that

Two balls are thrown simultaneously in the air. The acceleration of the centre of mass of the two balls while in air

A block moving in air breaks in two parts and the parts separate, then 

In an elastic collision,

A ball hits a floor and rebounds after an inelastic collision. In this case

A body moving towards a finite body at rest collides with it. It is possible that

In a head-on elastic collision of two bodies of equal masses