Question

A body is projected upward with velocity u.it passes through certain point above ground at t1.- the time after which the body passes through the same point during the return journey is

Answer 1

Let the starting point be A, point crossed by the ball be B and final point from where the ball returns be C.
For AC, v=0, u=u, and total time= t
0= u-gt
Or t= u/g ---eq.1
Now from A to B, time = t1 & from B to C, t= t2.
t = t1+t2 or t2 = t - t1.
But the ball comes back to the point B from C,
Implies that t2= 2(t- t1)
= 2(u/g - t1) is the final answer.

Answer 2

plz check the answer....