a ball tossed up at a rate of 8.7 ms/ and catches the ball at the same place on the way down. How long was the ball in the air?
V = Vo + g*Tr.
V = 0
Vo = 8.7 m/s.
g = -9.8 m/s^2.
Tr = ? = Rise time.
Tf = Tr = Fall time.
Tr+Tf = Time in air.