Question
A ball is thrown up with velocity 20m/s relative to ground in open lift moving up with speed 10m/s at time of throwing and has an acceleration of 2 m/s upward, ball meets lift after
Joshi sir comment
relative to lift
u of the ball = 20-10 = 10
a = 10-(-2) = 12 downward
and s = 0 because ball returns to initial point
now use s = ut + 1/2 a t2