A walk-in freezer requires 4.5×109J of electrical energy in one day. In the same facility, a compressor motor is rated 3.0 kW and operates for 6.0 h on that day.
a. (i) Calculate the electrical energy used by the motor in kilowatt-hours.
b. (ii) Convert the freezer’s energy use to kilowatt-hours.
c. (iii) State which device consumed more energy and by how much, giving the difference in megajoules.