Sci. 5 – 2

Energy Conversions

Pages 124- 130

A. Energy Conversions- a change from one form of energy to another

B.Any form of energy can be converted into any other form of energy.

C. Often Potential energy and kinetic energy convert back and forth like in a trampoline or a pendulum’s swing.

D. Light energy from the sun is used in photosynthesis to make sugar and oxygen in plants and food.

E. During photosynthesis plants convert light energy into chemical energy.

F. Electrical energy is easily converted into other forms of energy.

1) Hair dryer- sound, thermal, and kinetic

2) Alarm clock- light and sound

3) Light bulb- light and thermal

G. Machines can transfer energy and convert energy into a more useful form.

H. In a battery, chemical energy is converted into electrical energy.

I. Energy Efficiency- a comparison of the amount of energy before a conversion with the amount of USEFUL energy after a conversion.

J. Energy input is ALWAYS greater than energy output.