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Homework Help: Pendulum Question

  1. Apr 30, 2005 #1
    I'm having a problem with just one question on this week's physics quiz-
    a pendulum with length 2m on a moon oscillates 10 times in 32 seconds, what is the gravity on this moon?

    i know (or thought i knew) how to get the answer to this, with the simple formula g=4pi^2L/T^2

    10 oscillations in 32 seconds means a frequency of .32Hz, right? and T=1/f so T=3.125, right?
    so when i plug in T as 3.125 and L as 2, i get an answer of 8.08 m/s^2

    this is not one of the answer choices, however. my choices are 2.54, 9.86, 7.71, and 3.86
    what have i done wrong?
     
  2. jcsd
  3. Apr 30, 2005 #2

    Pyrrhus

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    Homework Helper

    Your approach is correct, Your arithmetic is wrong. The Period would be equal to 3.2
     
  4. Apr 30, 2005 #3
    Actually,you are not right.
    T=t/r=32/10=3.2 second.
     
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