Question

A ball is dropped vertically from a height d above the ground. It hits the ground and bounces up vertically to a height d/2. Neglecting subsequent motion and air resistance, its velocity v varies with the height h above the ground as

Answer 1

Correct option (a)

Explanation:

Before hitting the ground, the velocity Q is given by

v2 = 2gd

Further, v2 = 2g x (d/2) = gd;

∴ (v/v') = √2 or v = v'√2

As the direction is reversed and speed is decreased and hence graph (a) represents these conditions correctly