Electric Power is the rate at which energy converted or is used The watt W is a unit of power Since energy is measured in joules power is measured in joules per second One joule per second is equal to one watt ID: 326462
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Slide1
Electric PowerSlide2
Electric Power is the rate at which energy
converted or
is used.The watt (W) is a unit of power. Since energy is measured in joules, power is measured in joules per second. One joule per second is equal to one watt.
Power: is the rate at which the work is doneSlide3
Power
P = VI
Current (amps)
Voltage (volts)
Power (watts)Slide4
A light bulb with a resistance of 1.5Ω is connected to a 1.5-volt battery in the circuit shown at right.
Calculate the power used by the light bulb.
Calculate powerSlide5
A
kilowatt
(kW) is equal to 1,000 watts.The other common unit of power often seen on electric motors is the horsepower.One horsepower is 746 watts.Slide6
Electric companies charge for the number of kilowatt-hours used during a set period of time, often a month.
One
kilowatt-hour (kWh) means that a kilowatt of power has been used for one hour. Since power multiplied by time is energy, a kilowatt-hour is a unit of energy. One kilowatt-hour is 3.6 x 106 joules.
Paying for electricitySlide7
Your electric company charges 14 cents per kilowatt-hour. Your coffee maker has a power rating of 1,050 watts. How much does it cost to use the coffee maker one hour per day for a month?
Calculate
power