Howard Brody

Physics of the tennis racket

Several parameters concerning the performance of tennis rackets are examined both theoretically and experimentally. Information is obtained about the location of the center of percussion, the time a ball spends in contact with the strings, the period of oscillation of a tennis racket, and the coefficient of restitution of a tennis ball. From these data it may be possible to design a racket with improved playing characteristics.

Physics of the tennis racket II: The ’’sweet spot’’

The term sweet spot is used in describing that point or region of a tennis racket where the ball should be hit for optimum results. There are several definitions of this term, each one based on different physical phenomenon. In this paper the different definitions are discussed and methods are described to locate the points corresponding to each one.

How Would a Physicist Design a Tennis Racket

Tennis players dream of finding Lhe perfect racket that will immediately transform them into champions. While that may be wishful thinking, it is generally agreed that todays rackets are much better than those of 20 years ago. Though they may not turn you into an instant Wimbledon winner (after all, your opponent has one too), they will clearly improve your game. There is still hope among inventors, racket manufacturers and players that a perfect racket will come along someday. If and when such a racket is developed, what will its properties be and how will it affect the game of tennis?

The physics of tennis. III. The ball–racket interaction

A simple, one-dimensional, rigid-body model of a tennis racket interacting with a tennis ball agrees well with data taken when balls are fired at a stationary, free racket. The results are then transformed into the tennis court frame of reference, where the racket is moving. Data obtained on the rotational aspects of a tennis swing are then included in the model. For ground strokes, the results are used to predict strategies that will reduce unforced errors by players. The serve is then analyzed with respect to the current problem of the speed of the game. This paper is the third of a series of papers on tennis by this author. The two previous papers were “Physics of the Tennis Racket” [Am. J. Phys. 47, 482 (1979)] and “Physics of the Tennis Racket. II. The Sweet Spot” [Am. J. Phys. 49, 816 (1981)].

The sweet spot of a baseball bat

The physics of the three sweet spots of a baseball bat is discussed and the location of the ball impact point on the bat that leads to maximum ‘‘power’’ (greatest batted ball speed) is determined.

Models of baseball bats

By observing the vibrations of a hand‐held baseball bat, it is possible to show that the bat behaves as if it were a free body at the impact of the bat and the ball. The hand‐held bat shows none of the behavior of a bat with one end firmly clamped in a vise.