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!

The period of the resulting SHM

  1. Dec 5, 2007 #1
    I need some serious help for finding the angular frequency of this system

    The 3.81 kg cube has edge lengths d = 5.40 cm and is mounted on an axle through its center. A spring (k = 1100 N/m) connects the cube's upper corner to a rigid wall. Initially the spring is at its rest length. If the cube is rotated 3.00° and released, what is the period of the resulting SHM?

    Here's a picture to help..

    http://farm3.static.flickr.com/2108/2077 [Broken]...

    solution:

    From the ref, the moment of inertia I of a rectangular prism is m*(a^2+b^2)/12; for a cube with side d, I = md^2/6. At a distance r from the center the effective mass I/r^2 = (m/6)*d^2/r^2; since d/r = sqrt(0.5) it's m/12. Then ω^2 = k/(m/12).
    Since 3 deg is a small angle we can ignore the variation of r with rotation.

    question:
    i m just confused where the 12 came from???
     
    Last edited by a moderator: May 3, 2017
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted



Similar Discussions: The period of the resulting SHM
  1. Oscillation AND SHM (Replies: 4)

  2. SHM question (Replies: 18)

  3. SHM and Gravitation (Replies: 3)

  4. Period of satellite (Replies: 3)

Loading...