physics of spinning a golf ball backwards

If you have ever watched golf on T.V or even went to the PGA over at Oak Hill, you would have scene that every player was able to get their balls to hit the green and stop or spin backwards. They do this because they don't want their ball to roll of the green and cost him an extra stroke on that hole. But have you ever wondered how they are even able to do that by just hitting a ball with club? The answer is simple... PHYSICS!!

First of the a golf ball has dimples in it, what are these for you ask? well the dimples help the ball with air drag. More specifically, a thin layer of air clings to the surface of the ball at the front, and then passes over the ball as it moves, eventually breaking away from the surface at the back of the ball. This sets up little currents of turbulence behind the ball which slow it down. Dimples on the surface of the ball cause the air to cling to it longer. When the air finally breaks away from a dimpled ball, a narrower stream of turbulence is produced, which causes less drag. Therefore, the air drag causes much of the spin that is done on the ball rather than the club head and when the ball hits the green, the dimples in affect cause more friction when it comes into contact with the green. so when the amount of force of backspin on the ball has a positive net force going backwards the ball is going to head backwards when it reaches the green.