1 / 11

Chapter 4

Chapter 4. Energy. Work. Work is force applied over a distance. Expressed in units of foot-pounds (ft.lb.) or inch pounds (in.lb.). Power (P). Power is the amount of work done based on a time period such as seconds or minutes. Work. Force x Dist. Power =. =. Time. Time.

toya
Télécharger la présentation

Chapter 4

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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. Work Force x Dist. Power = = Time Time

  4. Horsepower (hp) • Horsepower is used for stating mechanical power. 1 hp = 550 ft.lb. / second In this much time This much work

  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. P (watts) = E (volts) x I (amps) 746 watts = 1 hp P=IE

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

  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 Power Company

  9. Efficiency • The ratio of electrical power out of a system to the electrical power in to a system. • Generally expressed as a percentage. Power Out % Efficiency = x 100 Power In

  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

More Related