Aball 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 8.0 s. what is its initial velocity? neglect air resistance

u=78.4m/s

Explanation:

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 8.0 s.What is its initial velocity? Neglect air resistance

from newtons equation of motion

s=ut

v=u+at

v=0 because at maximum height reached by the ball the ball stops moving

0=u-9.8*8

u=78.4m/s

u=initial velocity

v=final velocity

a=acceleration due to gravity, 9.81m/s^2

t=time it takes in air

s= distance to get to the maximum before returning