A player kicks a ball of mass 250 g placed at the center of the field. The ball leaves his foot with a speed of 8 m/s. Find the work done by the player on the ball.
Solution: The ball initially was static. As the player does some work on it by applying force, the ball gains kinetic energy (KE). So, we can say the work done on the ball equals its KE.
So, the work done = (1/2) m v2 = (1/2) (250/1000) 82 = 8 Joule