1. POWER Power – Power = P = ___=___ Units = ( ) = ____ = ___ Sample Problem: A crane lifts an 8000 N beam 75 m to the top of a building in 30 s. How much power does the crane use?

2. More Power Units Kilowatt (kw) = Megawatt (mw) Kilowatts = Horsepower = 1 horsepower =

3. POWER Power – Power = = Units = ( ) = = Sample Problem: A crane lifts an 8000 N beam 75 m to the top of a building in 30 s. How much power does the crane use? the rate at which work is done The rate at which energy is transferred from one object to another. work done time interval WFd t t WattW Nm s JsJs

4. P = W=Fd t t Force =Distance = Sample Problem: A crane lifts an 8000 N beam 75 m to the top of a building in 30 s. How much power does the crane use? 8000 N75 mTime =30 s P = 8000 N x 75 m 30 s 600,000 J 30s = 20,000 W or 20 kWP =

5. More Power Units Kilowatt (kw) = Megawatt (mw) Kilowatts = Horsepower = 1 horsepower = 1000 watts 1 million watts electricity (household electric bill) engines (cars are rated in).75 kilowatt