Question

A stone is projected upwards with a velocity of 120 m/s. With what
initial velocity should a second stone be projected upwards
2 seconds later so that it may overtake the first stone at its
maximum height?

Answer 1

Explanation:

time taken by first to reach max.height=10 seconds

if 2nd overtakes it at its max. height that means 2nd covers max height in 10s

u²/2g=u'10-1/2*5*10*10

120*120/2*10=u'10-250

u can proceed further