Question

Find the cost in dollars of the operating a 60-W lamp continuously for 1 week when the power utility rate is 18 cents/kWh .

Answer 1

Answer:

The cost in dollars is:

                       $ 1.8144

Step-by-step explanation:

It is given that:

The 60-W lamp is operated  continuously for 1 week.

We know that:

  1 week=7 days

and 1 day=24 hours

This means that:

     1 week=24×7

i.e.  1 week= 168 hours

Also, 1 kW=1000 W

This means that:

 1 W=0.001 kW

Hence,

 60-W=0. 060 KW

i.e. Power= 0.60 KW

Hence, the energy consumed is:

Energy=Power×Time

i.e.

Energy=0.060×168

i.e.

Energy=10.08 KWh

Also, cost of 1 KWh=18 cents

We know that:

1 cent=0.01 dollar

This means that:

18 cents=0.18 dollar

i.e.

Cost of 1 KWh=$ 0.18

Hence, cost of 10.08 KWh is: $ (0.18×10.08)

i.e.

Cost of 10.08 KWh is: $ 1.8144