Q . How do scientists define "work"? 2. What is a joule? What is the equivalent unit in the English system? 3. What is the difference between energy and power? What is a unit of power? 4. How do mass and speed relate to kinetic energy? 5. What is the relationship between heat, energy, and the motion of atoms? 6. Explain how sound is actually a form of energy. In what medium do sound waves travel? 7. What does it mean to say that different forms of energy are interchangeable? 8. Give examples of changes of energy from potential to kinetic and from kinetic to potential/ 9. What is a trophic level? Give some examples. How much energy is lost in moving from one trophic level to the next higher level? 10. Does the total amount of energy in an isolate system change over time? Why or why not?