Question

Suppose that the cost of electrical energy is $0.12 per kilowatt hour and that your electrical bill for 30 days is $60.00. Assume that the power delivered is constant over the entire 30 days. What is the power in Watts?

Answer 1

Answer: 690 W

Explanation:

A day has 24 hours, so a month has 24 × 30 = 720 hs

In a month whe spent a total of $60. 00, so per hour whe were  spending

$60/720 = 0.083$ $ per hour

We know the cost of one $kw/hour$  is  $0.012 kw/hour$ so dividing the money spent in an hour among this value we get:

$0.083/0.12 = 0.69 kw/hour$

This power delivered is constant, so every moment it is

$(0.69 kw)x1000 = 690Watts$