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!

Homework Help: Spring Equilibrium

  1. Oct 23, 2014 #1
    1. The problem statement, all variables and given/known data
    A mass (m = 1.20 kg), originally at rest, is attached to one end of an unstretched spring (k = 790 N/m) and the other end is fixed to a wall. The mass is then pulled with a constant force to stretch the spring. As a result, the system comes to a momentary stop after the mass is moved 14.0 cm. Find the:
    a) work done by the constant force
    b) change in potential energy of the spring --same answer as a)
    c) change in mechanical energy of the system --same answer as a)
    d) total work done by non-conservative forces --same answer as a)
    e) speed of the mass 4.00 cm into the motion
    f) the new equilibrium position of the system
    g) maximum speed of the mass and where it occurs

    The only question I have so far is f): why would the equilibrium position change? I am just looking for a conceptual answer here.
    Note: there is no friction anywhere

    2. Relevant equations

    3. The attempt at a solution
    Last edited: Oct 23, 2014
  2. jcsd
  3. Oct 23, 2014 #2
    think of the "additional constant force" like increasing the original mass. Since F = -kx, greater force means more displacement to get to equilibrium
  4. Oct 23, 2014 #3
    I should add that there is no friction anywhere*
    As far as I understand, equilibrium refers to the mean displacement of the simple harmonic motion. Though now I think equilibrium refers to dynamic equilibrium between forces. Is this correct?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted