Question

How many joules are there in $1$ kilowatt hour?

Answer 1

Step 1: Given Data

Power $P=1kW$

Time $t=1hr$

Step 2: Formula used

Energy $E=P\times t$

Step 3: Conversion to Joules

We know that,

$P=1kW=1000W$

Also,

$$\begin{gathered} 1hr=60min\times 60s \\ =3600s \end{gathered}$$

The unit of energy is joules.

Also, energy $E=P\times t$

$$\begin{gathered} =1000\times 3600Ws \\ =3.6\times {10}^{6}J \end{gathered}$$

Hence, $1$ kilowatt hour is equal to $3.6\times {10}^{6}J$.