a ball is thrown vertically upward and reaches a height of 15 cm. Find, a.) The projection velocity b.) the time of flight c.) the speed with w/c the ball passes the starting point

15cm? Wow.

at the top, vf=0

vf=vi-2g(.15) solve for vi

vf=vi-gt solve for time t at the top.
now time of flight is 2*t

vf=vi-g(2t)