A ball is thrown vertically downward with a velocity of 20 m/s from the top of a tower. It hits the ground after some time with a velocity of 80 m/s. The height of the tower is : (g = 10 m/s2 )

320 m 300 m 360 m 340 m

300 m

Use : v2 = u2 + 2 g h v = 80 m/s ; u = 20 m/s h = 300 m