Energy exists in different forms including light, thermal, sound, electricity, gravitational potential, and kinetic. Kinetic energy is the energy of moving objects and can be converted to electricity through wind and water turbines. Gravitational potential energy is stored energy that exists from height and springs and can be converted to kinetic energy. The principle of conservation of energy states that energy cannot be created or destroyed, only converted from one form to another. Work is the transfer of energy done by a force over distance, and power is the rate of work done or energy converted per unit time.

2. ENERGY
• The capacity to do work
• Work meaning making a body or machine move to achieve a purpose
• Can be converted from one form to another
• SI unit is joule (J)

3. DIFFERENT FORMS OF ENERGY AND ENERGY
CONVERSIONS
• Light
• Thermal
• Sound
• Electricity
• Gravitational Potential
• Kinetic

4. KINETIC ENERGY
• In all moving objects
• Used to do work; wind and waves can be used to turn turbines that
convert kinetic energy into electrical energy

5. GRAVITATIONAL POTENTIAL ENERGY
• Stored energy
• Can be converted to kinetic energy and vice versa
• Exists in many forms
1. Chemical Potential Energy- In the food we eat
2. Elastic Potential Energy- A spring or rubber band possesses this energy
when compressed
3. Gravitational Energy- When an object is raised to a certain height
above the ground, it possesses this energy

6. PRINCIPLE OF CONSERVATION OF ENERGY
• Energy can neither be created nor destroyed in any process. It can be
converted from one form to another or transferred from one body to
another, but the total amount remains constant

7. WORK
• When an object moves under the influence of a force
• Work done by a constant force on an object is given product of the
force and the distance moved by the object in the direction of the force
• W= F x S
 W= work done by a constant force F
 F= constant force
 S= distance moved by the object in the direction of the force

8. POWER
• The rate of work done or rate of energy conversion
• SI unit is watt (W)
• One watt is the rate of work done at 1 joule per second