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: SHM Spring System is Independent of Gravity?

  1. Apr 3, 2015 #1
    For a mass-spring system,
    Period, T = 2pi * root(m/k)

    So using hookes law,
    F = kx
    But if the spring is being stretched by a mass due to gravity,
    mg = kx
    So,
    k = mg/x

    But then this means,
    Period, T = 2pi * root(mx / mg)
    or,
    T = 2pi * root(x / g)

    Where have I gone wrong? I've been told countless times that a spring-mass system's period is independent of g, but it seems my proof states otherwise.

    Thanks
     
  2. jcsd
  3. Apr 3, 2015 #2

    TSny

    User Avatar
    Homework Helper
    Gold Member
    2017 Award

    Hlello, GameJammer. Welcome to PF!

    Just to make sure, what is the precise meaning of x in this equation? Is it an arbitrary value of x or some specific value of x?
     
  4. Apr 3, 2015 #3
    x is the extension of the spring, it's part of Hookes law
     
  5. Apr 3, 2015 #4

    TSny

    User Avatar
    Homework Helper
    Gold Member
    2017 Award

    Yes. But it's the extension of the spring under what condition?
     
  6. Apr 3, 2015 #5
    It's the extension of the string due to force F
     
  7. Apr 3, 2015 #6

    TSny

    User Avatar
    Homework Helper
    Gold Member
    2017 Award

    Does x in your equation k = mg/x represent how much the spring is stretched if you just hang the mass on the spring and let it sit in equilibrium? Or does it represent something else?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted