Re: How does friction stop a ball from rotating while also slowing it down?

Hello, Will

If the ball is not rotating before it is released, it requires friction to roll. Let's say the ball isn't rolling before it is released. On the first bounce, the bottom of the ball will scrape the ground while the top of the ball's motion is unimpeded. This turns a portion of the ball's kinetic energy into rotational energy, with some lost to friction. Kinetic energy is the energy the ball has from its forward motion. Rotational energy comes from the ball's rotation.

The velocity of the rolling is proportional to the forward velocity. The ball will reach an equilibrium so that there is no sliding. Now we have a mix of kinetic and rotational energy. As it continues to roll, the ball's rotational energy is lost due to friction, so it rolls slower. When the ball rolls slower, more of the ball's kinetic energy is converted into rotational energy, which causes the ball to slow down in its forward motion. Therefore, friction causes the ball to slow its rotation and forward motion.

I hope that I've answered your question adequately. For more information, look at the websites below. Thanks for your question,

Kevin

Properties of Sliding and Rolling Croquet Balls (Dr. Ian Plummer)

Friction and Rolling Balls (Argonne National Laboratory)