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 done by a spring

  1. Feb 28, 2010 #1
    1. The problem statement, all variables and given/known data

    http://img205.imageshack.us/img205/7536/capturebb.jpg [Broken]

    i am stuck on part c

    how do i find work with out using the spring constant

    2. Relevant equations

    work equals force parallel times displacement at which the force is acted during...

    Work done by spring = .5 kx^2
    Work = delta K

    but delta K = 0 because the table top is frictionless

    Work = delta U
    delta U = 0 in this situation correct?

    3. The attempt at a solution

    so I'm stuck...

    i think it might be zero but .5 kx^2 would not give zero now would it...
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Feb 28, 2010 #2


    User Avatar
    Homework Helper

    The work done on the block by the spring is equal to the change in KE of the block.
  4. Feb 28, 2010 #3
    hmmmmmmmm.... so then.... um.....
  5. Feb 28, 2010 #4
    ok thanks
  6. Feb 28, 2010 #5
    wait so to find the spring constant...

    is delta U = delta K = W = .5 kx^2

  7. Feb 28, 2010 #6
    - (Mg)/(2h)
  8. Feb 28, 2010 #7


    User Avatar
    Homework Helper

    0.5 kx^2 = 0.5 Mv^2.
    From the given data you can find v.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook