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Period of a pendulum?

  1. Sep 30, 2006 #1
    I have this question:

    You are doing some spring cleaning and decide to clean out your house. You want to make a new window in your wall with which to see nature come to life, so you tie a heavy mass to a short string and attach the string to a beam in your ceiling so it can swing freely like a pendulum. You lift the ball and let it go for practice, and it takes exactly 0.5 s to come right back to you. Ready for the real thing, you quadruple the length of the pendulum. Were it to swing freely also, it would take ____ s to return to you after you let it go.

    So I went over the equation for a period quite a few times and tested a few calculations to make sure and finally concluded that the period would be quadrupled if the length is quadrupled.

    The equation for a period is (in the book):

    period of a pendulum = 2(pi) * ((sqrt)(length of pendulum/acceleration due to gravity))

    Was my conclusion right? My answer was 2 seconds.
  2. jcsd
  3. Sep 30, 2006 #2
    Not quite period goes as sqrt{L} i.e increasing the length by 4 increases the period by 2
    Last edited: Sep 30, 2006
  4. Sep 30, 2006 #3

    Got it. I'm dumb, and very sleepy.
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