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Homework Help: Simple Harmonic Motion, Urgent, Please

  1. Aug 28, 2011 #1
    1. The problem statement, all variables and given/known data
    a particle moves to the right along the x axis with a simple harmonic motion from x0 = 3.0cm in t=0 . if its position x is given by x = 4.0 cos (pi t + phi) , in cms ; find its period T.

    2. Relevant equations

    3. The attempt at a solution

    The problem ask me more things like the aplitude, phi and others but the amplitude i found was 4.0cm and phi was 41.1 . Now im stuck because im asked more things such as the angular frequency and more the equtions for the velocity , acceleration and more but I need T or omega in order to find those. How can I find T?

    My guess is that the problem already suggests T but im starting to learn about harmonic motion so I dont see things clearly for now can anyone give em soem help in order to find T or the angualr frecuency ?

    Thanks lot in advance.
  2. jcsd
  3. Aug 28, 2011 #2


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    Homework Helper

    The period refers to the length of time from when something happens, to what it happens the next time.

    What value of t gives a maximum x value?
    What next value of t will also give the maximum x value?
    the difference in those two is the period.

    Note we use an extreme value, since the particle undergoing SHM is at each intermediate position twice during a cycle - but traveling in the other direction.
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