3_Power - Energy and Power Power Power • Most appliances...

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Unformatted text preview: Energy and Power Power Power • Most appliances have a Most label listing the # of watts (or kilowatts). Voltage (volts) P=V I P=V • A watt (W) is a unit of power. Power is the rate at which watt (W) energy is flowing. • 1 watt = 1 Joule per second. watt Current (amps) Power (watts) Ex: A 100 W light bulb uses 100 Joules of energy every second. Ex: How can you get more power? Increase voltage Standard outlets are 120 V Standard Increase current Decrease resistance Gauge of wire Gauge Watts and kilowatts Remember metric conversions? Our base unit: watt Kilo means ____________ Therefore, a kilowatt is Therefore, _________watts. _________watts. A 1500 watt toaster oven is the same 1500 as a _______kilowatt toaster oven. as 1 Kilowatt-hour (Unit of Energy!) You buy electricity by the kilowatt-hour You kilowatt (kW⋅h). Means 1 kilowatt of power used for 1 Means hour. hour. At your home, a meter measures kW⋅h At kW used. A meter reader visits once a month used. to obtain the reading. Your electric bill is based on that kW⋅h kW reading! Estimating your electrical charges The 1050 W means how The many watts used. many Typical charge is 14 ¢ / Typical kW⋅h. kW Problem: The coffee maker is on for one hour each day. How Problem: much will it cost to run per month? Average watt usage on appliances appliances If you add up all of If the appliances you use, you can estimate how much your electric bill will be. 2 ...
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This note was uploaded on 11/13/2011 for the course PHYS 1111 taught by Professor Plascak during the Fall '08 term at UGA.

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