1. Not finding help here? Sign up for a free 30min 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!

Reading of a pendulum clock from the earth to the moon

  1. Jan 28, 2008 #1
    A certain pendulum clock that works perfectly on Earth is taken to the moon, where g = 1.62 m/s^2. Acceleration of gravity is 9.81 m/s^2 on Earth. THe clock is started at 12:00:00 AM and runs for 22 h.

    What will be the reading for the hours on the moon? answer in h

    T = 1 second
    g = 9.81
    T = 2pi * square root of length/g or rearrange into g (T/2pi)^2 = l
    l = 0.248

    g = 1.63
    T = 2pi * square root of l/1.63
    T = 2.453

    22h * 3600s = 79200 sec
    79200/2.453 = 32286.99552
    32286.99552/3600 = 8.9686 hours



    i also tried

    22*3600 = 79200s
    79200 = 2pi * square root of l/9.81
    l = 1557100708
    T = 2pi *square root of 1557100708/1.63
    T = 194197.8499s
    194197.8499s / 3600 = 53.9438472 hr
     
    Last edited: Jan 28, 2008
  2. jcsd
  3. Jan 28, 2008 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Answer these questions:
    (1) Does the clock run slower or faster on the moon?
    (2) What's the ratio of the moon period to the earth period?

    (One of your answers is correct, but you did more work than needed.:wink:)
     
  4. Jan 28, 2008 #3
    i tried those answers and it says both were wrong
     
  5. Jan 29, 2008 #4

    Doc Al

    User Avatar

    Staff: Mentor

    It's not clear what format the answer must have. Sounds like X hours, like you have. But it could also mean the time, as in 5:17:34 PM.

    In any case, the ratio of periods is:

    [tex]T_m/T_e = \sqrt{\ell / g_m} / \sqrt{\ell / g_e} = \sqrt{g_e / g_m}[/tex]

    Thus [itex]T_m = 2.46 T_e[/itex], so the clock on the moon is 2.46 times slower than the clock on earth.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Reading of a pendulum clock from the earth to the moon
  1. Pendulum clock (Replies: 4)

Loading...