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: Calculating Work Done

  1. Apr 21, 2010 #1
    1. The problem statement, all variables and given/known data
    A box of weight 100N is pushed a distance or displacement of 2m with a force of 40N. What is the work done on the box by i) the weight and ii) by the 40N force?

    2. Relevant equations
    Work = force * distance

    3. The attempt at a solution
    i) The work done on the box by weight = 0 (if this is correct, why?)

    ii) The work done on the box by the 40N force
    Work = force * distance
    Work = 40 * 2
    Work = 80N
  2. jcsd
  3. Apr 21, 2010 #2
    Work, force, and displacement are vectors. Can you figure out "why" from there?
  4. Apr 21, 2010 #3


    User Avatar
    Gold Member

    I'll just say ths, work done by weight is 0 because that fat box did not helping you out AT ALL :grumpy:

    Now, if it was on an incline sliding down as you pushed it..
  5. Apr 21, 2010 #4
    Let me see... weight is acting vertically downwards, while force and displacement are acting horizontally. Therefore the weight had no influence on the force and displacement?

    Thanks very much, you made it clearer
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook