How many joules are in a kilowatt-hour?

[Mangastream]

Homework Statement

How much energy (in Joule units) is in a kilowatt-hour?

Homework Equations

The Attempt at a Solution

 

[gneill]

What's the definition of a watt?

 

[DavidFitz]

Fairly simple, let's break down what a Watt is. We know that it is the rate of energy, or a Joule/second (J/s)

If we are given a kWh, this is actually a measurement of energy, or energy usage. If power is measured per unit time, and we multiply by time, the units cancel with one another.

P * t = E

P = 1000 W (1 kW = 1000 W)
t = 3600 seconds (60 seconds in a minute * 60 minutes in an hour)

1000 W * 3600 s = 3,600,000 J