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!

Hard potential energy function question

  1. Oct 17, 2011 #1
    1. The problem statement, all variables and given/known data
    Potential energy function A particle of mass m, starting from x = −∞, approaches
    a force region whose potential is given by
    V (x) =(ka^2)/((x^2)+(a^2))
    where V0 > 0 and a are constants.
    (a) Derive an expression for the force on the particle as a function of

    2. Relevant equations

    E=F/Q, V=W/Q, E=V/d

    3. The attempt at a solution

    I tried to substitute it into the equations above, but it didn't work. A friend thought the answer involved calculus, but I'm not sure where to start. Any hints would be much appreciated...
     
  2. jcsd
  3. Oct 17, 2011 #2
    Is it correct that potential x mass = potential energy?
     
  4. Oct 17, 2011 #3
    Do I need to introduce a constant for the charge, of can I express F without this? Help, please! Thanks! :-)
     
  5. Oct 17, 2011 #4

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    No.

    Check your thread which directly asks this question.
     
  6. Oct 17, 2011 #5

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    You don't need the charge.

    You can express F without introducing a charge.

    Do you know how to take the gradient?

    F = - V .

    Otherwise, F = - dV(x)/dx .
     
  7. Oct 17, 2011 #6
    Thanks SammyS, you post about the gradient answers the question perfectly!

    :-)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Hard potential energy function question
Loading...