1. The total amount of energy in a closed system always remains the same.
2. A comparison between a conversion’s useful output energy to the input energy.
3. Nuclear energy comes from changes in the nucleus of a atom. Light energy travels in waves called electromagnetic waves.
4. The chemical energy in a battery is converted into electrical energy that powers a flashlight.
5. The electrical energy in a light bulb is converted into light energy. Unfortunately, it is also converted into heat energy.
6. (45 J/120 J) x 100% = 37.5%
7. The cheering of the crowd. The chemical energy of the food the jumper ate. The jumper soaring through the air.
8. The chemical energy of the jumper’s food is converted into mechanical energy as he move. His kinetic energy is converted into potential energy as he jumps.
9. Electromagnetic energy from the sun is converted into chemical energy by plants. When you eat a plant, you take in this chemical energy. You convert the chemical energy into kinetic energy when you move your body.