10. A skateboarder travels down a slope. At which point does he have his greatest kinetic energy?

11. A pendulum is a mass on a string that swings back and forth to some angle. When is the kinetic energy at its maximum?

12. For a pendulum or mass on a string that swings back and forth to some angle, when is the kinetic energy at its minimum.

13. Which culture was the first to think that energy could not be destroyed?

14. skateboarder travels down a slope and up the other side. At which point does he have his least kinetic energy?

15. A hot pie is hotter inside than outside. Why?