# KW to kWh

1. Jun 1, 2017

### Onoff32

1. The problem statement, all variables and given/known data

If I calculate that a motor needs 41kW continuously throughout a day to run, and it costs $0.08 per kWh to run, to calculate the cost of this for 32 weeks, I would do 41 x 24hours x 7days x 32weeks x$0.08 = \$17633.28

is this a correct way of working it out?

2. Jun 1, 2017

### Staff: Mentor

Your number is are correct, but your units don't make any sense.

Here's what you should have, including the appropriate units.
$41 kW \times 24 \frac{\text{hours}}{\text{day}} \times 7 \frac{\text{days}}{\text{week}} \times 32 \text{weeks} \times .08 \frac{}{\text{kWh}} = 17,633.28$.
The day units cancel, the week units cancel, and the kWh units cancel, so you're left with dollar units.
41 kW times 1 hour = 41 kWh, or 1 kW times 41 hours = 41 kWh, as well.