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Homework Help: Simple Harmonic Motion

  1. Mar 13, 2008 #1
    _{}b]1. The problem statement, all variables and given/known data[/b)

    The position of a 39.8 g oscillating mass is given by the equation x(t)= (2.00cm)cos(5t- 4.00[tex]\pi[/tex]) where t is in seconds. Determine Velocity at t= 0.250s

    M= 39.8 g
    T= 1.2575 rad/s
    K= 9.95e-1 N/m
    initial postion= 2 cm

    2. Relevant equations

    V[tex]_{x}[/tex]= -[tex]\omega[/tex]Asin([tex]\omega[/tex]t + [tex]\phi[/tex])
    3. The attempt at a solution

    the attempt i just substitued
    V[tex]_{x}[/tex]= -5 rad/s*2sin( 5.00(0.250)-4[tex]\pi[/tex]).... but this didn't work and i dont understand why???
     
  2. jcsd
  3. Mar 13, 2008 #2
    for the the equations posted its supposed to be V subscript x= wAsin(wt + phi) and x(t) = (2.00cm)cos(5t - 4pi)
     
  4. Mar 14, 2008 #3

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    What is the basic relation connecting velocity and position of any particle? Use that.
     
  5. Mar 14, 2008 #4
    it seems work to me...
     
  6. Mar 14, 2008 #5
    Your right it does work, i guess I entered in the wrong units when i answered the question( m/s instead of cm/s).
     
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