Question

Convert 1 kilowatt hour into joule.

Answer 1

We have seen that: energy (kWh) = power (kW) × time (h)

Normally we want energy in joules (J) and time in seconds (s). The kW above is 1000 W (1000 J/s). The hour is 3,600 seconds, so:

1 kWh = 1,000 J/s × 3,600 s

1 kWh = 3,600,000 J

$1kWh=3.6\times {10}^{6}J$