A ball falls from a height of 5 m and strikes the floor of the lift, which is moving upwards with a velocity of 1 m/s. What is the velocity of rebound of the ball? Assume the collision to be elastic.

Q: A ball falls from a height of 5 m and strikes the floor of the lift, which is moving upwards with a velocity of 1 m/s. What is the velocity of rebound of the ball? Assume the collision to be elastic.

(a) 12 m/s

(b) 9 m/s

(c) 6 m/s

(d) 3 m/s

Ans: (a)