Newton's Laws

The tennis serve relates directly to Newton’s third law of motion. Newton’s third law of motion states, “for every action there is an equal and opposite reaction” (Blazevich, 2010). When looking at the tennis serve, the primary force is the impact of the racquet on the tennis ball. The impact of the racquet onto the ball propels the ball over the net and across the court to the opponent. The reactant force is the ball on the racquet, which causes the strings to move. This is confirmed when watching a slow motion video (click the link below) of a tennis ball making contact with the racquet. You can clearly see the impact of both the racquet onto the ball and the opposite force of the ball onto the racquet.


http://www.youtube.com/watch?v=pufedQgGYzg

The tennis serve also links to Newton’s second law of motion. The second law of motion states “The acceleration (a) of a body is parallel and directly proportional to the net force (F) acting on the body, is in the direction of the net force, and is inversely proportional to the mass (m) of the body, i.e., F = ma” (Blazevich, 2010). This means that the force exerted, measured in Newton’s, is equal to the mass of an object multiplied by it’s acceleration. Assuming that all tennis balls are equal in mass, what separates different players’ serves is the acceleration that each individual can place on the ball, while still maintaining accuracy. The greater the force of the tennis serve, the more difficult for the opponent to return the serve.