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: Spring max depression

  1. Oct 22, 2004 #1
    Ok I was wondering if someone could help me with this problem i'm not sure how to set uo the problem in order to solve it using kinetic and potential energy. Thank you heres the question.

    An 80.0-kg man jumps from a height of 2.50 m onto a platform mounted on springs. As the springs compress, he pushes the platform down a maximum distance of 0.240 m below its initial position, and then it rebounds. The platform and springs have negligible mass.
    What is the man's speed at the instant he depresses the platform 0.120 m?
    If the man just steps gently onto the platform, what maximum distance would he push it down?
  2. jcsd
  3. Oct 22, 2004 #2
    You know [itex]F_{spring}=-kx[/itex] and [itex]E_{elastic potential}=\frac{1}{2}kx^{2}[/itex]. Can you go from there? Try using free-body diagrams and thinking about the transfer of energy here.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook