Two identical balls are shot upward one after another

PHYSICS · Single correct · CBSE · Physics · Gravitation · Gravitation

Problem

Two identical balls are shot upward one after another, at an interval of

2\text{ s}

, along the same vertical line with the same initial velocity of

40\text{ m s}^{-1}

. The height at which the balls collide is (1)

50\text{ m}

(2)

75\text{ m}

(3)

100\text{ m}

(4)

125\text{ m}