A 240-V clothes dryer draws a current of 15 A. How much energy, in kilowatt-hours and in joules, does it use in 45 minutes of operation?
Gives
Voltage (v)=240V
Current (i)=15A
Time=45min=0.75h
We know that
"P=\\frac{E}{t}"
"E={P}\\times{t}"
Where P=power
E=energy
t=time
When
P"=IV"
Put value
"P=15\\times240=3600W"
"E=3600\\times0.75Wh"
"E=2700Wh"
Energy found kWh
"E=\\frac{2700}{1000}=2.7KWh"
1KWh="3.6\\times10^6J"
E="2.7\\times3.6\\times10^{6}J"
"E=9.72\\times20^6J"
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