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: Hooke;s Law! PLease Help!

  1. Oct 16, 2008 #1
    Q: How does the force constant of two springs hung linearly compare with the individual force constant??
    What would be the equation that relates the total force constant, to the individual force constants, k1 and k2, of two springs joined together linearly??

    A: The Total force constants is gonna be k1 + k2??
    Last edited: Oct 16, 2008
  2. jcsd
  3. Oct 16, 2008 #2

    Andrew Mason

    User Avatar
    Science Advisor
    Homework Helper

    You should show some work.

    Apply a force W = mg by hanging a mass m at the end of the bottom spring(2) (do it so the springs are stationary after stretching). The bottom end of spring 1 will have stretched x1 from its top end and spring 2 a further distance x2 from spring 2's top end.

    Do a free body diagram for the forces on m. What are the upward forces? What are the downward forces on m? What do they sum to?

    Do that and you should see what the answer is and why.

  4. Oct 16, 2008 #3
    Draw the springs and the forces. Write the appropriate relationship between forces and deformations.
    If by "linearly" you mean something like one after another (series), k is not k1+k2.
  5. Oct 17, 2008 #4
    Re: Hooke's Law! Please Help!

    Thanks a lot guys. I get it now.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook