1000 joules of energy are put into a pulley system, and 400 joules come out. What does the Law of Conservation of Energy imply about the lost energy?
Choices:
1) The pulley system could be improved to conserve some of the lost energy.
2) The lost energy is not truly lost, but it changed into a different form.
3) The lost energy is caused by friction.
4) The lost energy cannot be recovered.
The Law of Conservation of Energy states that energy cannot be created or destroyed, only transferred or transformed from one form to another. Therefore, the correct answer is:
2) The lost energy is not truly lost, but it changed into a different form.