How to find efficiency of a motor

Question

2. An electric motor operates a pump that irrigates a farmer’s crop by pumping 1.0×104L of water a vertical distance of 8.0 m into a field each hour. The motor has an operating resistance of 22.0 Ohm and is connected across a 110-V source.

a)What current does the motor draw?

b)How efficient is the motor?

Please show work thanks!

)

How efficient is the motor?

Answer 1

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Answer 2

a) Current I = v/R = 110v/22Om = 5 A

b) efficiency of motor: η= mgh/(VIt) = 104kg·9.81m/s²·8m/(110V·5A·3600s) = 0.00412 = 0.412%