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How does a tennis racket change the motion of a tennis ball?

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Title page of Isaac Newton's Philosophiae Naturalis Principia Mathematica, 1687, featuring large Latin text and publication details in a bordered layout. — Newton’s laws of motion The title page of Isaac Newton's *Philosophiae Naturalis Principia Mathematica* (1687; *Mathematical Principles of Natural Philosophy*), the work in which the physicist introduced his three laws of motion.

When a tennis racket strikes a tennis ball, it changes the ball's motion by exerting a force upon it. According to Newton’s first law, an object remains at rest or in uniform motion unless acted upon by a force; the impact from the racket provides this external force, causing a sudden change in the ball's velocity and direction.1

This interaction is also governed by Newton’s third law, which states that for every action, there is an equal and opposite reaction. Consequently, the force the racket exerts on the ball is equal and opposite to the force the ball exerts on the racket, which the player perceives as the shock of the impact.1

Furthermore, Newton’s second law explains that the force applied by the racket results in the acceleration of the ball. Because the rate of change of momentum is equal to the strength of the applied force, the racket effectively alters the ball's motion by changing its momentum through the force of the swing.1