Final answer:
The kilowatt-hour (kWh) is a unit of energy that results from using power at a rate of 1 kilowatt for the duration of one hour. It is used for measuring electricity consumption on electric bills and can be equated to 3.6 million joules.
Step-by-step explanation:
The unit kilowatt-hour (kWh) is commonly mistaken but is precisely defined as a measure of energy. This confusion arises because it includes the term kilowatt, which is a unit of power. However, when we multiply this power by time (hours), we obtain energy. Power is the rate at which energy is used or transformed, and energy is what is accumulated or spent over time. Therefore, a kilowatt-hour is calculated by taking the power in kilowatts (kW) and multiplying it by the time in hours (h), with the equation E = Pt, where 'E' is energy, 'P' is power, and 't' is time.
Indeed, electricity bills utilize the kilowatt-hour as a unit of energy to quantify how much electrical energy a household has consumed. It’s a convenient metric because electrical appliances generally consume power in kilowatts and often run for multiple hours. To put it into perspective, 1 kilowatt-hour (kWh) is equivalent to 3.6 million joules (J).