3. Assume your electric bill showed you used 1355 kWh over a 30-day period. a.) Find the energy used, in kJ, for the 30 day period. b.) Find the energy used in J/day. c) At the rate of $.0749/kwh, what will your electric bill be for this month

4.87×10⁶ kJ

1.63×10⁸ Joules

1015 $

Explanation:

a. To convert the units, you can use this conversion factor:

1 kWh = 3.6×10⁶J

1355 kWh . 3.6×10⁶J / 1 kWh = 4.871×10⁹ J

Now we convert to kJ →  4.87×10⁹ J . 1 kJ/1000J = 4.87×10⁶ kJ

b. In 30 days, we used 1355 kWh so, let's determine the use by day

1355 kWh / 30 day = 45.2 kWh

Now we convert the 45.2 kWh to Joules → 45.2 kWh . 3.6×10⁶J / 1 kWh =

1.63×10⁸ Joules

c. We can make a rule of three, for this:

1 kWh costs $0.749

1355 kWh will pay (1355 . 0.749) / 1 = 1015 $