Question

A lift is coming down with a downward acceleration of 2m/s2 .A boy standing in the lift throws a stone vertically upwards with speed 5m/sw.r.t himself. The time after which he will catch the stone is

Answer 1

a=2m/s². s=5m/s. t =? let u be 0 (initial velocity)

s=ut +½at ²

5=0t + ½(2t)²

5=0+½4t²

5=4/2 t²

5=2t²

5/2 =t²

2.5= t²

t=0.5

t=0.5