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 by spring

  1. Oct 9, 2004 #1
    I have a problem I need help with:
    A block lies on a horizontal frictionless surface and is attached to the free end of the spring, with a spring constant of 35 N/m. Initially, the spring is at its relaxed length and the block is stationary at position x = 0. Then an applied force with a constant magnitude of 2.8 N pulls the block in the positive direction of the x axis, stretching the spring until the block stops.
    Assume that the stopping point is reached. What is the position of the block?
     
  2. jcsd
  3. Oct 9, 2004 #2

    Gokul43201

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    What's the problem with the problem ? Draw a force diagram. You know how to calculate the force due a stretched spring...do it.
     
  4. Oct 9, 2004 #3
    I've tried the formula F(spring) = -kx and got -.08 but thats not the answer.

    It seems to me when the mass stops the applied force will equal the spring force
     
  5. Oct 9, 2004 #4
    next time try posting in the homework help section
     
  6. Oct 9, 2004 #5

    Gokul43201

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    And check your sign. Read what the question says about which direction (positive or negative x-direction) the block is pulled.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook