1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

Work and conservative forces

  1. Oct 25, 2008 #1
    1. The problem statement, all variables and given/known data

    Suppose a force acts on an object. the force does not vary with time, nor with the position or velocity of the object. Start with the general definition of work done by force, and show that the force is conservative

    2. Relevant equations
    W = FX
    Wnonconservative = KE final PE final - KE initial - KE final

    3. The attempt at a solution
    I started with W = FX
    W = E final - E initial
    E = KE f + PE f - KE i - PE i
    W = 0 + PE f - O - PE i Since KE is a non-conservation force and there is only a conservative force.
    W = PE f - PEi Since PE f = PE i if PE is a conservative force
    w = 0

    The answer doesn't make any sense... Any suggestions?
    Last edited: Oct 26, 2008
  2. jcsd
  3. Oct 25, 2008 #2


    User Avatar
    Homework Helper

    Hi zoner7,

    This line not true. Saying that KE is a non-conservative force is not true.

    I would suggest you start with some definitions. What is the general formula for the work done by a force? And also, what is the definition of a conservative force?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook