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Homework Help: Simple oscilation

  1. Mar 27, 2010 #1
    1. The problem statement, all variables and given/known data
    A body is suspended vertically from an ideal spring of spring constant 3.5 N/m. The spring is initially in its relaxed position. The body is then released and oscillates about its equilibrium position. The motion is described by the following equation.

    y = (4.5 cm) sin [(0.62 rad/s)t]

    What is the maximum kinetic energy of the body?
    [answer in mj)


    2. Relevant equations

    Kmax=.5kA^2

    3. The attempt at a solution

    .5(3.5)(.045)^2=.003543 J but the answer must be in mj. So, 3.543x10^-9 BUT computer did not accept the answer as a correct one... Could anyone help me please?
    Thanks!
     
  2. jcsd
  3. Mar 27, 2010 #2

    rl.bhat

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    1 mJ equal to how many Joules?
     
  4. Mar 27, 2010 #3
    .003543 joules = 3.54300 × 10-9 megajoules
    so if my answer is correct, then it is the machine error that it's not being accepted. is my answer correct?
    Thanks
     
  5. Mar 27, 2010 #4

    rl.bhat

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    Homework Helper

    mJ is milli joule i.e. 10^-3 J. Mega Joule is MJ = 10^6 J
     
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