1. Chapter 4 Energy

2. Work Work is force applied over a distance. Expressed in units of foot-pounds (ft.lb.) or inch pounds (in.lb.)

3. Power (P) Power is the amount of work done based on a time period such as seconds or minutes.

4. Horsepower (hp) Horsepower is used for stating mechanical power.

5. Watt (W) Watt is the unit of electrical power. 1 watt of power is when one volt of electrical pressure moves one coulomb of electricity in one second Note: one coulomb in one second is an amp.

6. Watt’s Law P = I x E I = P / E E = P / I

7. Ohm’s Law and Watt’s Law

8. Wattmeter and Watt-Hours Electrodynamometer movement – electromagnetic movement found in watt meters Wattmeter – meter that measures instantaneous power. Watt-hour meter – measures the amount of power used in a period of time. Kilowatt hour (kWh) – 1000 watt-hours

9. Efficiency The ratio of electrical power out of a system to the electrical power in to a system. Generally expressed as a percentage.

10. Energy Efficiency Rating A rating by the government to show the energy efficiency of electrical appliances. Larger the percentage the more efficient the unit.

11. Gears, Pulleys and Power Law of conservation of energy – energy cannot be created nor destroyed. It can only be converted from one form to another