Question

A ball is thrown vertically upward, which is the positive direction. A little later it returns to its point of release. The ball is in the air for a total time of 8.33 s. What is its initial velocity? Neglect air

Answer 1

Given:

$t=8.33\:\rm s$

The time of motion upward and downward is the same.

Hence, the time of motion upward

$$t_1=t/2=8.33/2=4.165\:\rm s$$

The initial velocity

$$v_0=gt_1=9.81*4.165=40.9\: \rm m/s$$