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Homework Help: Pendulum type questions

  1. Apr 28, 2010 #1


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    1. The problem statement, all variables and given/known data

    1. A long pendulum has time period 10s. If the bob is displaced 2m from the equilibrum position and released, how long will it take to move 1m ?

    2. As a mass on a spring travels upwards through the equilibrium position, its velocity is 0.5m/s. If the frequency of the pendulum is 1Hz what will be the velocity of the bob after 0.5s ?

    2. Relevant equations

    [tex] v=-v_{o}\sin{\omega t} [/tex]
    [tex] x=x_{o}\cos{\omega t} [/tex]

    3. The attempt at a solution

    I've tried to use the formulas above, but it didn't work for me. These questions are supposed to be easy.
  2. jcsd
  3. Apr 29, 2010 #2


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    Staff Emeritus
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    Homework Helper

    For #1, use your equation x=x0cos(ωt).
    Just plug in the values for x, x0, and ω. Then solve it for t.
    (You will need to figure out the value of ω first.)
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