Tiger Woods can hit a golf ball with 55 N of force. How hard does the ball hit back on the club? (a) more than 55 N of force, (b) less than 55 N of force, (c) exactly 55 N of force. Explain (c) Exactly 55 N;
Newton's 3^{rd} law. The ball accelerate because the club is held by Tiger and that combined mass is much bigger than the mass of the ball, so the ball experiences a larger acceleration.