The Physics of Tennis

If you are taking tennis lessons I hope your pro is explaining why certain ball reactions happen. The best instructors have the ability to teach the same thing by explaining it different ways. I may explain something one way but it is not understood by the pupil, having multiple explanations allows one of them to make sense to the student.

Let’s go over some of the basic principles using some physics to have you understand why the ball reacts the way it does.

You hear all the time that for basic forehand and backhand drives that the correct swing is low to high, this is correct for the simple reason that you have to overcome gravity. The net is thirty nine feet from the baseline; if there is not a low to high swing the ball cannot clear the net. The problem that arises is that if you are putting power on your shot keeping the ball from going long is difficult. This is where topspin comes into play; if you read my blog often you know that spins are the controlling factor in your shots. Topspin is created by brushing up the backside of the ball causing a forward rotation. Physics comes into play when the air mass the ball must travel through will push the ball downward, after some distance, because of the forward ball rotation. So, a hard shot with no spin will travel until gravity forces it to come down, usually out of the court, and a hard shot with topspin will come down inside the court due to the air pushing the forward spinning ball down.

The opposite is true for backspin or slice shot. To create backspin the shot is hit with a high to low swing brushing down the backside of the ball. The same air mass that pushes down on a forward spinning ball will lift a backward spinning ball. This is why the slice shot is appropriate for low balls, especially short low balls.

One more area of tennis where you should know the physics involved is power. Let’s quickly go over two areas, one in ground strokes and then the serve. Power is created by head speed. The greater the arc of the swing the harder the ball can be struck. If you are too close to the ball when hitting you will have to pull the arm in closer to the body which will shorten the arc of the swing, resulting in loss of power. The same is true on the serve. The lower the contact point when serving the shorter the arc, losing power. You want the serve at your full extension to form the longest arc possible for maximum power.

For more tips and my book Winning Tennis Strokes, go to http://onlinetennistraining.com.

Good luck … have fun!
 

Centercourt
USTA NTC

January/February 2024 Digital Edition