How much energy in kilowatt-hours does a 700-watt block heater use in 6 hours?

To determine how much energy a 700-watt block heater uses in 6 hours, you can use the formula for energy consumption, which is:

Energy (in kilowatt-hours) = Power (in kilowatts) × Time (in hours)

First, convert the power from watts to kilowatts. Since 1 kilowatt (kW) is equal to 1000 watts (W), the 700-watt block heater can be converted as follows:

700 W = 0.7 kW

Next, plug the converted power rating and the time into the formula:

Energy = 0.7 kW × 6 hours = 4.2 kWh

Thus, the energy consumed by the heater in 6 hours is 4.2 kilowatt-hours. This calculation illustrates how to apply the principles of electrical energy usage based on the power rating and operating time, reinforcing the concept of utilization of power appliances in terms of kilowatt-hours.