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Homework Help: Harmonic motion problem

  1. May 5, 2008 #1
    Hi everyone,

    Could someone please help me with this problem?

    1. The problem statement, all variables and given/known data
    In an engine, a piston oscilates with simple harmonic motion so that its position varies according to the following expression, where x is in centimeters and t is in seconds.

    a. At t=0, find the position of the piston
    b. What is its velocity?
    c. What is its acceleration?
    d. Find the period and amplitude of the motion

    2. Relevant equations

    3. The attempt at a solution

    a. 5cmcos(3(0)+pi/5)=5cos(pi/5)=4.05cm

    b. -5sin(pi/5)=-2.9

    c. -5cos(pi/5)=-4.05

    d. 5cm=amplitude

    Thank you very much
  2. jcsd
  3. May 5, 2008 #2


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    [tex]v=\frac{dx}{dt}=-5sin(3t+\frac{\pi}{5}) \times 3=-15sin(3t+\frac{\pi}{5}) [/tex]
  4. May 5, 2008 #3
    Thank you very much

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