1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: KW to kWh

  1. Jun 1, 2017 #1
    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. jcsd
  3. Jun 1, 2017 #2


    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.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted