The potential energy of a projectile at its maximum height is equal to its kinetic energy there . If the velocity of projection is 20m/s its time of flight is ?

Answer 1

m g h = ½ m v²

h = v² / (2 g)

h = ½ g t² ... v² / (2 g) = ½ g t²

t = v / g .. this is ½ the flight time

Answer 2

125