A ball of mass 0.2 kg rests on a vertical post of height 5 m . A bullet of mass 0.01 kg , traveling with a velocity $\mathrm{V} \mathrm{m} / \mathrm{s}$ in a horizontal direction, hits the centre of the ball. After the collision, the ball and bullet travel independently. The ball hits the ground at a distance of 20 m and the bullet at a distance of 100 m from the foot of the post. The velocity V of the bullet is