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!

Simple Harmonic Motion MCQ Question!

  1. Sep 7, 2009 #1
    1. The problem statement, all variables and given/known data

    A simple pendulum was moving in front of a horizontal scale. the extreme positions of the bob were at the 300mm and 500mm marks. The bob moved from the 350mm to the 450mm marks in 1.0s. What is the period of the oscillations?
    A. 2.0s
    B. 3.0s
    C. 4.0s
    D. 6.0s

    2. Relevant equations

    x = x0 sin(wt + fai) , where "fai" is the phase difference.
    fai/2pi = x/wavelength, x is the distance apart between 2 points out of phase.
    T=2pi/w , where T is the period and w is the angular velocity.

    3. The attempt at a solution

    i tried solving by using x0=100,
    taking 400 to be the equlibrium point, since it was middle of 300 and 500.
    thus, amplitude is x0=100.
    so by the formula x = x0 sin(wt + fai),
    i still need to find fai and x.
    so i used fai/2pi = x/wavelength.
    and then i'm stuck.. ):

    any help would be appreciated. thank you!
  2. jcsd
  3. Sep 7, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Your starting equation is OK, but the phase is an irrelevant complication here. If you clock starts when the pendulum is at the equilibrium position, the equation is simply

    x(t) = A sin(ωt) with A = 100 m.

    Note that 350 mm is -A/2 and 450 mm is +A/2. This should help.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Simple Harmonic Motion MCQ Question!
  1. Simple Harmonic Motion (Replies: 3)

  2. Simple Harmonic Motion (Replies: 2)

  3. Simple harmonic motion (Replies: 4)

  4. Simple Harmonic Motion (Replies: 3)