Question

A ball of mass m moving with velocity V, makes a head on elastic collision with a ball of the same mass moving with velocity 2V towards it. Taking direction of V as positive velocities of the two balls after collision are

• A. – V and 2V
• B. 2V and – V
• C. V and – 2V
• D. – 2V and V

Answer 1

Answer: (D)

– 2V and V

Answer 2

Initial velocities of balls are +V and – 2V respectively and we know that for given condition velocities get interchanged after collision. So the velocities of two balls after collision are – 2V and V respectively.