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Homework Help: Harmonic Motion/ max VelocityPlease Help

  1. Apr 28, 2006 #1
    An object with mass 3.5 kg is attached to a spring with spring stiffness constant k = 300 N/m and is executing simple harmonic motion. When the object is 0.020 m from its equilibrium position, it is moving with a speed of 0.55 m/s.

    b) Calculate the maximum velocity attained by the object. [Hint: Use conservation of energy.]

    so if i use E= 1/2mv^2=1/2KX^2
    then-->.5(3.5 kg)(.55) ^2= 1.5(300 N/m)(.200) ^2

    but what does that prove ? I dont think this is right
     
  2. jcsd
  3. Apr 28, 2006 #2

    Andrew Mason

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    Science Advisor
    Homework Helper

    You are right - your answer is not right.

    Just add the kinetic and potential energy to find its total energy. Energy is conserved. So when potential energy = 0, kinetic energy = total energy. That is where it will have maximum speed.

    AM
     
  4. Apr 28, 2006 #3
    That piece of information lets you calculate the potential and kinetic energies (at the point .02m from equillibrium). With that you can calculate the total energy of the system(E = P+K). Now how is this connected to the maximum velocity the object can have?
     
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