# The Science of Sledding

The top of the hill. Anticipation. The ride down. Stimulation and Trepidation. The bottom of the hill. Satisfaction.  We can learn some physics principles through the science of sledding.

These three stages, the top, the ride down, and the bottom, are examples of energy in action.

At the top you have potential energy, you have energy stored, just by being a high place from which you can fall or slide down. If you didn’t your sled would just sit there, you would never fall down the hill, instead you would have to push all the way down, no matter how slick or steep the hill. While you are sliding down the hill you still have potential energy, the rest of your ride, but that potential energy is getting less and less as you approach the bottom of the hill. You are gaining more and more kinetic energy as you approach the bottom of the hill. Kinetic energy is the energy of motion. When you get to the bottom of the hill, your kinetic energy is maxed out and your potential energy is gone.

The people at the top of the sledding hill had to work hard to walk up there. On the way they were gaining potential energy. That’s why the ride down will be so effortless. They have stored the energy during the climb up the hill.

Nathan is part way down the hill. He still has quite a bit of potential energy but he’s using it up fast. It is being converted to kinetic energy, the energy of motion.

Garrett is at the bottom of the hill. He used up all of his potential energy. It was converted to kinetic energy. In a frictionless world he would have never stopped moving. But friction and sound used up his kinetic energy and that energy was lost.

Energy never disappears, but is changed from one form to another.  So where does all that kinetic energy go that you have at the bottom of the hill? Most of it goes to heat and sound. To make the swooshing sound of your sled sliding over the snow requires energy. And though there’s not much heat, the friction of your sled against the snow does produce heat, enough to slow your sled at the bottom of the hill.