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Homework Help: Archived Simple Harmonic Motion - Spring-Pendulum-Mass System

  1. Nov 19, 2008 #1
    1. The problem statement, all variables and given/known data

    A pendulum of length L with a bob of mass M hangs vertically. The bob is attached to a horizontal spring that has a force constant k. When the bob is directly below the pendulum support, the spring is unstretched. (a) Derive an expression for the period of the oscillating system for small amplitude vibrations.

    2. Relevant equations

    x = Acos(wt)
    w = 2pi/ T
    E = 1/2 k A^2
    w = sqrt (k/m) for a spring
    w = sqrt (g/ L) for a pendulum

    3. The attempt at a solution

    I'm pretty sure I need to use energy for this problem but I'm having trouble understanding the system itself.
  2. jcsd
  3. Mar 4, 2017 #2
    Draw a picture if it helps.

    Since you're given the force constant for the spring it might be easier to consider the forces on the bob.
  4. Mar 4, 2017 #3


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