Step-by-step explanation:
We know that kWh is a commercial unit of energy.
Also, 1 Joule = 1 watt × 1 seconds
![1\ kWh=1kW * 1\ h](https://img.qammunity.org/2021/formulas/physics/high-school/g8gt1w5ntqv4bwhlqmh4ezajsildisht2t.png)
Since ,1 h = 3600 s and 1kW = 1000 W
![1\ kWh=1000\ W * 3600\ s\\\\1\ kWh = 36* 10^5\ W-s\\\\1\ kWh=36* 10^5\ J](https://img.qammunity.org/2021/formulas/physics/high-school/cl4o4rikg63u7j62pinfcpl54jmavi3seg.png)
So, the relation is :
![1\ kWh=36* 10^5\ J](https://img.qammunity.org/2021/formulas/physics/high-school/fxc9ewankkq3zg3iowb1xy4o5uzg77gkar.png)
1 watt is defined as the power of an appliance when the energy is transferred at a rate of 1 Joule per second.