Physics of the Golf Swing
Hitting a powerful drive takes more than just strength and coordination, it also requires the physics concepts of torque, centripetal force and something known as the double pendulum effect. "Science of Golf" is produced in partnership with the United States Golf Association and Chevron.
DAN HICKS reporting: It's the big drive that leads off almost every hole: the tee shot.
PAULA CREAMER (2010 U.S. Women's Open Champion): Your number one goal is to move the ball as far as you possibly can and in the straightest direction.
MIKE MILLER (Amateur Golfer): I feel I can hit it anywhere with the driver.
HICKS: Hitting a powerful drive takes more than just strength and coordination, it also requires three physics concepts: torque, centripetal force and something known as the double pendulum effect.
JOHN SPITZER (Equipment Standards, USGA): What happens is you can use physics to allow the forces to do the work for you.
HICKS: To explore the physics of a golf swing, we filmed Paula Creamer, a professional golfer on the LPGA tour, and amateur golfer Mike Miller with a Phantom camera that captured their drives at 5,000 frames per second.
Known as the "Pink Panther" because she loves the color pink, Paula Creamer has won 11 tournaments including the U.S. Women's Open in 2010.
Creamer's shots are most notable for their accuracy.
CREAMER: I don’t miss many fairways, I don’t miss many greens at all. I pretty much swing within myself.
HICKS: Part of the reason for Creamer's success on the golf course is her ability to master the double pendulum effect.
A pendulum is a weight suspended from an anchor from which the weight can pivot or swing freely under the influence of gravity.
SPITZER: If you look simply at a clock, an old grandfather clock that you might have in your living room or your hallway, the thing that goes back and forth is the pendulum. And it’s the simplest of motion about an arc.
HICKS: John Spitzer is Managing Director of Equipment Standards at the United States Golf Association. He says that during a drive there are actually two pendulums at play. Creamer's arms make up the first pendulum, which moves or pivots around her anchoring shoulders. Her wrists are the pivot for the second pendulum below it: her golf club.
SPITZER: As that pendulum swings, the one on the bottom swings independently.
HICKS: If the double pendulum is executed properly, it can make the golf swing feel effortless.
CREAMER: You know instantly if you hit a great one, if you hit a little thin, a little heavy, a little bit on the toe, a little bit on the heel.
MILLER: And then when you do connect, absolutely perfect, you know.
HICKS: As of May 2013 Mike Miller is ranked 9th in the United States in amateur golf. His drives are most notable for their distance.
MILLER: That’s one of the of the strongest parts of my game is driving.
HICKS: Miller's swing displays the second physics concept: centripetal force, or a force that makes an object move in a curved motion.
Much like a roller coaster speeding around a loop, centripetal force is what keeps the cars turning instead of flying off the track into space.
Miller creates centripetal force by anchoring his lower body and pulling his wrists inward while the golf club swings outward and through the second pendulum.
SPITZER: As you’re further away from the center or the rotation, you’re getting more speed.
HICKS: The bigger the circle the less centripetal force is needed to continue rotating the golf club so that it can move faster, and therefore hit the ball farther.
CREAMER: The more you can turn and the more you can get that big arc in your swing, the farther you should be able to hit it.
HICKS: But the most important factor to a big tee shot is the third physics concept: torque, or force times distance, is a turning force that changes the rate of rotation in an object.
SPITZER: If you look at the swing as a whole, you’re looking at torque as the main thing in an actual golfers swing.
HICKS: Think of a wrench tightening a bolt, the longer the wrench, the more torque it creates. Both Creamer and Miller apply torque throughout their entire swing by rotating their shoulders during the back swing and then twisting their hips as they bring the club down to strike the ball.
CREAMER: You’re rotating as much as you possibly can with your shoulders and then you’re just letting it go with your hips.
HICKS: The more turning force Creamer and Miller apply to their swings the faster and more powerful their drives will be.
MILLER: I was able to notice that, how much torque I’m creating. I never really thought about it until you really see it in slow-mo with the phantom camera. And it’s really cool.
HICKS: Torque, centripetal force and the double pendulum effect - the key concepts in the physics of a golf swing.