1. Not finding help here? Sign up for a free 30min 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!

Is a simple pendulum simple harmonic motion?

  1. Oct 17, 2009 #1
    I'm wondering this because my textbook says that for small angles it is, but we learned that for simple harmonic motion to occur there must be a linear restoring force.. eg F= -kx.. but for the simple pendulum the restoring force is F= -mgsin(theta).. wouldn't this not be linear?
     
  2. jcsd
  3. Oct 17, 2009 #2

    rock.freak667

    User Avatar
    Homework Helper

    Well you see for small angles θ, sinθ≈θ so that the restoring force is F=-mgθ.

    And now you know θ=x/l (x=arc length and l=length of pendulum)

    so F=-mgx/l
     
  4. Oct 17, 2009 #3
    Ohh okay, makes sense. Thank you!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Is a simple pendulum simple harmonic motion?
Loading...