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: Work Done on a particle

  1. Apr 17, 2016 #1
    1. The problem statement, all variables and given/known data
    A -2.0*10^-3 C charge is 0.2 m away from a -6.0*10^-3 C charge. How much work is must be done on the first charge to move it to a distance of 0.9m?

    2. Relevant equations
    F = qs*qt*k/r^2

    W = F * d* cos theta

    3. The attempt at a solution
    =2700000 N
    =220408.1633 N

    W = 2700000N * .2 = 540000
    W = 220408.1633 * .7 = 154285.7143

    The sum of those is 694285.7143

    This is obviously not right because the answer is supposed to be -4.2*10^5
  2. jcsd
  3. Apr 17, 2016 #2
    I think It is easy to use potential method, first calculate the potential difference 0.2m to 0.9m due to the second charge,
    the use the eqn, W=qV
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted