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Homework Help: Period of a Pendulum

  1. Nov 21, 2011 #1
    I am getting confused regarding what a 'period' in a pendulum is.
    In a recent Olympiad/Exam I was given this question.....
    Can you please give me the method in which it can be done
    so that I can solve these type of questions with ease if they
    appear in future.....
    Thanks :smile:
    A Pendulum oscillates between positions L and R as shown in the figure. It takes 1.2 s to go from L to R and back to the mean position S what is the PERIOD of the pendulum?

    From my point of view the answer should be 1.6 seconds.....
    that's what I wrote as an answer but i'm not very
    sure so I just want to confirm....:redface:

    Thanks a Lot!:smile:
    Last edited: Nov 21, 2011
  2. jcsd
  3. Nov 21, 2011 #2

    Simon Bridge

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    Science Advisor
    Homework Helper

    The period of the pendulum it the time it takes to complete a single swing.

    I know that sounds obvious - but when you get confused you should return to the actual physics of the situation and then build the math.

    That is a really bad picture :)
    A whole swing goes from L to R then back to L again.
    (if it starts at L that is)

    L -> R is half a period
    L -> S is a quarter period.

    So if that was your reasoning, you did well.

    Extend yourself:
    If you put an additional point P half-way between L and S, what proportion of the period is the time to swing from L to P?
  4. Nov 21, 2011 #3
    Thnx a Lot Simon Sir!
    I didn't know what a period is (i'm just in the 6th grade :P) so I
    assumed it is something like L - S - R - S - L.......
    Thnx for the clarification :smile:
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