Learn how to do a 360 or a 180 by going to Tony Hawk's web site and downloading video clips of tips. If you make a complete circle with your skateboard, you've done a 360, because there are 360 degrees in a circle. The world champ, Tony Hawk, can ace a 900, two and a half turns off a vertical ramp. You have lots of it. So do roller coasters.
Kinetic energy is the energy of an object in motion.
On a roller coaster energy changes from kinetic energy to potential energy when going uphill, and from potential energy to kinetic energy on the way down. But the total amount of energy remains the same, no matter what form it takes. Stretch the paper out on the floor or a long table, with the books stacked at one end. Open the additional book approximately to the middle and prop it up against the stack of books to make a ramp. Line all but one of the marbles side by side in the track made by the rulers.