A ball falls freely from a height of 45m. When the ball is at a height of 25 m, it explodes into two equal pieces. One of them moves horizontally with a speed of 10 . The distance between the two pieces when both strike the ground in m  is

Let at the time explosion velocity of one piece of mass  is (10 ). If velocity of other be , then from conservation law of momentum (since there is no force in horizontal direction), horizontal component of , must be .

 Relative velocity of two parts in horizontal direction

Time taken by ball to fall through 45m,

 and time taken by ball to fall through first 20m, . Hence time taken by ball pieces to fall from 25 m height to ground .

 Horizontal distance between the two pieces at the time of striking on ground

m