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Homework Help: Very annoying question

  1. Dec 9, 2009 #1
    1. The problem statement, all variables and given/known data
    I'm sorry to bother anyone but this question is really driving me insane. It's one of my question on my notes and I've been trying to re-solve it.
    It's in oscillatory unit and apparently we have to know what the speed is.

    A 4.00kg mass is an horizontal frictionless surface attached to a spring with k=20.0N/m. The mass is pulled 0.300m from a equilibrium, then let go.

    2. Relevant equations
    max speed

    3. The attempt at a solution The answer is suppose to be 0.671m/s but I keep getting 0.612m/s...

    ..Never mind I figured it out.
    Last edited: Dec 9, 2009
  2. jcsd
  3. Dec 9, 2009 #2
    so W=.5*20*.3^2=.9

    since the max speed is when all the energy is kinetic you can say the Wspring=(1/2)mv^2
    so .9=.5*4*v^2

    sqrt(.45)=.6708 or .671
  4. Dec 9, 2009 #3
    Thank you for replying, I'm very happy but I already solved it.

    I just remember, when you told me, that kinetic energy is in there since it's in motion. Again, thank you and I'm very sorry.
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