Tennis Courts and Equipment: How Physics Affects the Speed of Play

tennis ballsTennis is played internationally.  Depending on what nation hosts a tennis tournament, players may find themselves competing on anything from grass (Wimbledon) to clay (Australia) to rubber coated concrete with acrylic paint (U.S.).  Other variables within the sport include ball types and rackets.

Different court surfaces, balls, and rackets impact the speed of the game. One way to address the issue of speed is to combine a faster court with a slower ball, or a slower court with a faster ball, to level out the pace.  Additionally, scientists continue to study the composition of rackets, shoes, balls, and court material to find solutions to these and other ongoing issues in the sport.

Learn the basics of how physics affects the speed of play or read the more technical explanation.

Articles by Lindsay Sanford

Creating the Perfect Golf Ball with Chemistry

white-golf-ballThe composition of golf balls has evolved through the years. Two-layered balls, which are inexpensive and popular,  have come a long way.  Polymers combined with natural compounds from rubber have been used to create golf balls that have good distance, high abrasion resistance, and optimal firmness.  Scientists are beginning to research ways to prolong the life of balls after they are exposed to moisture.

Brief the basic chemistry principles or read the more technical chemistry explanation.

Articles by Jessica Egan

Understanding Head Injuries Through Biomechanics and Math


In biomechanics, systems in motion — such as the impact of a ball on a player’s head — are described or “modeled” by mathematical differential equations. For example, these equations can show the relationship between the acceleration or force of the ball to the head at impact, and the change in shape of brain tissue in response to that form. The solution to these equations provides information that could be used to establish new safety regulations or adequate sports gear for players.

Current studies show that heading the ball may not be as much of a concern as physicians and parents thought, although it is not fully understood how repetitive head shooting, through many years of play, affects players. Further research will continue to help treat and prevent injuries, and improve athlete performance through individualized coaching.

Learn more about the basics of head injuries and biomechanics or read the more technical mathematical explanation.

Article by Cristian Clavijo

From Tee to Fairway: How Physics Affects the Drive, the Club, and the Golf Ball

Golf Ball Velocity

Golf Ball Velocity

The average golfer drives the golf ball with an initial velocity of over 100 miles per hour.  If the player uses a club with a flexible shaft, the act of swinging adds an additional measure of torque as the head of the club also propels forward to connect with the ball.  The head of the club has grooves that increase the friction between the club and the ball, allowing the club to more effectively focus the area of contact.

The optimal angle to hit the ball ranges from about 12 to 20 degrees.  Putting a backspin on the ball increases lift and can add significant distance to the drive.  The dimples on the golf ball itself help reduce drag from the air stream by reducing turbulent air pressure around and behind the ball, shifting the wake further behind the ball, thus allowing for smoother, less resistant flight.   Any combination of these variables contributes to how well the ball overcomes the forces of gravity and air resistance.

Learn the basics of how physics affects golf or read the more technical details here.

Articles by Trevor Stoddard

Creating the Perfect Golf Ball with Chemistry (Basic)

Gowf, as the Scottish first called it, had humble beginnings in eastern Scotland as a game played with wooden balls and clubs (Mallon, 2011).  Since its humble beginnings, golf has grown to be a sophisticated sport growing ever more so as researchers pump all of their expertise into the game in a quest to make the ideal ball.

The first modern golf ball consisted of a small, hard core wound with a long string of rubber and then coated with tree gum called gutta-percha (Mallon, 2011).   Since then, many improvements have been made on golf balls to give them the perfect “feel” (i.e. a certain resilient, soft feel that golfers look for when their clubs make contact), but also great durability and wear and tear resistance. These two qualities tend to be mutually exclusive in a single material; however, scientists have developed balls with several layers, each layer addressing a specific need that the ball has.

Researchers have targeted polymers, a long molecular chain made of many smaller subunit molecules linked together, as the best materials for golf balls. This is because polymers are very flexible – by changing even one atom in the subunit or twisting the subunit slightly, a polymer can go from being used for the hard golf ball cover to the more elastic inner layer.

Figure 1: A – chemical structure of natural rubber, B – chemical structure of gutta-percha

An example of how a slight difference between polymers makes a big difference in the ball is seen between gutta-percha and natural rubber, as seen in Figure 1 (Goodman, 1974; Yikmis,Steinbüchel, 2012). The lower structure is gutta-percha, which was replaced in golf history by natural rubber, the upper structure. As can be seen, rubber has more kinks in its structure, making it a better molecular spring than the more rigid gutta-percha. This spring-like quality made the ball compress more when struck, thus transferring more energy to the ball’s flight when the molecules “pushed off” the club.

Golf balls have other important pieces to them, such as the cover. The cover of a golf ball must be able to withstand up to 10,000 N (Penner, 2003) of force without cracking and also be able to take repeated hits without wearing down. The entire ball must be able to snap back into its original shape without any damage to itself or its properties from the momentary deformation that occurs when it is hit with the club. The ideal ball would have a perfect transfer of energy between the club and the ball, so that none of the golfer’s force is wasted.

How can a perfect ball be manufactured? A perfect ball would be easy to manufacture, being made from polymers that easily release from their mold, thus preventing damage to the ball if it had to be pried from its mold. The best golf balls to date are multi-layer balls, which have four layers devoted to a specific purpose: middle layers that are compressible and elastic, the cover that is hard and resilient, and an inner core that is rigid to maintain form (Giffin, 2002). Even with such high-tech polymer balls, other challenges remain: can scientists develop a polymer to do all that has been required of it previously and prevent moisture from seeping into the ball and compromising its integrity?

Learn the technical chemistry in creating the perfect golf ball.

By: Jessica Egan, University of Utah
Jessica Egan began her love of chemistry under her mom’s direction with homeschool experiments in middle school and then up into high school through her high school chemistry teacher. She pursued a chemistry and art double major at Hillsdale College and decided to continue her chemical education by attending graduate school at the U. She has recently graduated with a M.S. from the U in Analytical Chemistry and is looking for a career in industry.