Question

A rubber ball of mass 0.12 kg is held at a height of 2.5 m above the ground, then released.
Calculate the velocity of the ball before it reaches the ground.

Answer 1

Change in potential energy = Kinetic Energy

m*g*h = (1/2)*m*(v^2)
9.8 * 2.5 * 2 = v^2
49 = v^2

v = 7 m/s

Answer 2

V^2 = Vo^2 + 2g*h = 0 + 19.6*2.5 = 49,
V = 7 m/s.