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: Simple Harmonic Motion Problem(pendulum)

  1. Oct 22, 2008 #1
    1. The problem statement, all variables and given/known data
    A simple pendulum is made from a 0.653 m-long string and a small ball attached to its free end. The ball is pulled to one side through a small angle and then released from rest. After the ball is released, how much time elapses before it attains its greatest speed?

    2. Relevant equations


    incase that didn't come out right using the symbols: Timeofpend=2pi*the square root of length divided by gravity

    3. The attempt at a solution
    I used this equation from notes in class and the answer was wrong... I'm not sure whether you need to factor in kinetic energy/potential energy because it's asking the time before it attains the greatest speed or not. I feel like this should be an easy question. Thanks ahead of time! :-)
  2. jcsd
  3. Oct 23, 2008 #2
    Remember your equation gives the time for one complete oscillation. Think of where the pendulum's speed will be a maximum (at which position) during it's swing? The law of conservation of mechanical energy will help you to determine this point.
  4. Oct 23, 2008 #3
    ok got it thanks!
  5. Oct 24, 2008 #4
    Glad to be of assistance :smile:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook