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Homework Help: Another simple harmonic motion question

  1. Jan 17, 2010 #1
    1. The problem statement, all variables and given/known data

    A particle of mass m begins at rest from x = +24 cm and oscillates about its equilibrium position at x = 0 with a period of 1.4 s. Write expressions for the following. (Enter your numerical values to two decimal places.)

    (a) the position x as a function of t

    I solved for omega using omega = 2pi/T where T is 1.4. This gave me the answer 8.9759s. I then plugged everything I knew into the equation x = Acos(omega*t) giving .24cos(8.9759*t). Apparently, this is wrong. It might actually be because of it asking me to put it into two decimal places, but I want to make sure I am correct before I put an answer in. (Webassign is very picky.) Is there a phase constant in this instance? I'm thinking no. If so, would .24cos(8.98t) be my correct answer?
  2. jcsd
  3. Jan 17, 2010 #2
    Try calculating the angular frequency again :) I got 4.49.
  4. Jan 17, 2010 #3
    Ah, you're right... dumb math errors. Is that the only mistake I made? Is the correct answer then .24cos(4.49t) ?
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