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the input power to a motor is 12w the motor wastes 590 j of energy in 1 min what is the efficiency?
the answer is 18. can someone explain how?
the answer is 18. can someone explain how?
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Physics question.
- Thread starter Waania
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PlanetMaster
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Effeciency is output power over input power.
The input power is 12w.
And since the motor "wastes" 590j of energy in 1 min, the power "wasted" can be calculated with
[imath]E=P \times t[/imath]
[imath]P = \frac{E}{t} = \frac {590}{60} = 9.83[/imath]
So output power is [imath]12-9.83 = 2.17[/imath]
And thus,
[imath]Effeciency = \frac{output power}{input power} \times 100 = \frac{2.17}{12} \times 100 = 18%[/imath]