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Homework Help: Simple harmonic oscillators and a pendulum clock.

  1. Sep 30, 2011 #1
    Hey physics forums, this is my first post and frankly I'm having trouble conceptualizing this problem. I know harmonic oscillation is involved, as it is a pendulum. However, I know I have to incorporate g into the s.h.o. equation and I'm not quite sure how to do that. Any help would be greatly appreciated.


    1. The problem statement, all variables and given/known data
    A pendulum clock which keeps correct time at a point where g=9.8 m/s^2 is found to lose 10 seconds per day at a higher altitude where the gravitational field now has a new value g(n). What is the numerical value of this g(n)?


    2. Relevant equations
    This is from the force diagrams I've drawn.
    Tcos(theta)-mg=ma(x)
    Tsin(theta)=ma(y)

    I'm lost. Please help!
     
  2. jcsd
  3. Sep 30, 2011 #2

    PeterO

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    Homework Helper

    The period of a pendulum with small amplitude - like you find on a clock - is related to the length [which doesn't change] and g [which is changing]
    I think this problem is more about proportional or percentage change than re-deriving the formula for a pendulum.
    The other trick is to work out whether the clock is running fast or slow in the mountains, and what that says about the pendulum.
     
  4. Sep 30, 2011 #3

    gneill

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    Staff: Mentor

    Are you expected to derive the period of a pendulum from first principles, or can you use the (well known) formula directly? It can be found in a few seconds with a web search.
     
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