Two balls A and B having masses 1 kg and 2 kg, moving with speeds 21 m/s and 4 m/s respectively in opposite direction, collide head on. After collision A moves with a speed of 1 m/s in the same direction, then the coefficient of restitution is

Two ball A and B having masses 1kg and 2kg, moving with speeds 21m//s amd 4m//s repectively in opposite direction, collide head on. After collision A moves with a speed of 1m//s in the same direction, then correct statements is:

Two smooth spheres A and B of equal radii but masses 1 kg and 2 kg move with speeds 21m/s and 4 m/s respectively in opposite directions and collide. The velocity of A is reduced to 1 m/s in the same direction. Then, which of the following statements is incorrect?

Two particles A and B of equal size but of masses m kg and 2 m kg are moving directly towards each other with speeds 21 m/s and 4 m/s respectively. After collision, A moves with a speed of 1 m/s in the original direction. Then:

Two particles A and B of equal size but of masses m kg and 2m kg are moving directly towards each other with speeds 21 m//s and 4 m//s respectively. After collision, A moves with a speed of 1 m//s in the original direction. Then:

Two spheres of masses 1 kg and 2 kg are moving with velocities of 10 m/s and 5 m/s respectively in the same direction. After the collision the velocity of the lighter sphere decreases by 4 m/s. What is the coefficient of restitution?

A ball A of mass 3 kg and a ball B of mass 4 kg are moving alogn the same straight line with speeds of 7m/s and 5 m/s respectively. They approach each other and collide. What is the speed of B after collision, If the coefficient of restitution is 3/4 ?

A 60 kg body moving with speed 12 m/s collides inelastically with another body of mass 50 kg moving in same direction with speed 2 m/s. After collision the 50 kg body moves with a speed of 10 m/s. The value of coefficient of restitution (e) is :-

Two particle moving in the same direction with speeds 4 m//s and 2m//s collide elastically (the collision being head on). After collision , the velocity of first particle becomes 3 m//s in the same direction . The velocity of the second should be

Two particles of mass 1 kg and 0.5 kg are moving in the same direction with speed of 2 m//s and 6 m/s respectively on a smooth horizontal surface. The speed of centre of mass of the system is

Two particles of mass 1 kg and 0.5 kg are moving in the same direction with speed of 2 m//s and 6 m/s respectively on a smooth horizontal surface. The speed of centre of mass of the system is