Lesson 4:3 - Conservation of Energy

Which of the following is NOT true?

• Energy cannot be created or destroyed.

• Mechanical energy is the sum of kinetic energy and thermal energy.

• Energy can be transferred from one place to another.

• Energy can be converted from kinetic energy to gravitational potential energy.

What type of energy transformation occurs when bread is toasted in a toaster?

• kinetic to thermal

• chemical potential to thermal

• chemical potential to thermal

• electrical to thermal

Suppose you are swinging on a swing. When will your gravitational potential energy be the greatest?

• at the bottom of your path

• when you are rising

• at the top of your path

• when you are falling

A swing’s chains rub on their hooks as they move back and forth. Which statement is true?

• Friction converts mechanical energy into thermal energy.

• Air resistance converts thermal energy into friction.  

• Air resistance converts thermal energy into mechanical energy.  

• Friction converts thermal energy into mechanical energy.  

Which type of energy transformation occurs when a green plant grows?

• chemical potential energy to radiant energy

• gravitational potential energy to radiant energy

• kinetic energy to chemical potential energy

• radiant energy to chemical potential energy