Question

If a ½ hp pump runs for 21 minutes, what is the energy used in kW-hr?

Answer 1

1 HP = 0.75 kW

$\frac{0.75}{2} = 0.375 \;kW \; per \; 21\; min$

Proportion:

0.375 kW – 21 min

x kW – 60 min

$x = \frac{0.375 \times 60}{21} = 1.071 \;kW-hr$

Answer: 1.071 kW-hr