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Homework Help: Impulse on a sliding block attched to spring

  1. Jan 23, 2009 #1
    A 4kg wooden block resting on an icy surface (so friction can be ignored) is attached to a horizontal spring (L=1m, k=100N/kg), which is attached on the other end to a vertical wall. A 2g bullet is fired at a speed of 100m/s into the wooden block, pushing it directly toward the wall. What is the period and amplitude of the resulting oscillations?



    f=(1/2pi)sqrt(k/m)



    I have no clue?
     
  2. jcsd
  3. Jan 23, 2009 #2
    Re: Oscillation

    A good starting point would be to calculate how much energy the bullet transfers to the spring-block system.

    Also (I'm sure it was a typo, but) the spring constant, [itex]k[/itex], can never take the value N/kg. [itex]k[/itex] is a measure of restoring force per unit length of displacement, so the S.I. unit is N/m.
     
  4. Jan 23, 2009 #3
    Re: Oscillation

    okay... I got T=1.2s and A=45cm ... is this correct?
     
  5. Jan 23, 2009 #4

    LowlyPion

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    Re: Oscillation

    Not sure how you arrived at your amplitude. Your period looks about right, though I would check to see that you rounded correctly.
     
  6. Jan 23, 2009 #5
    Re: Oscillation

    Looks good to me. (Just to be pedantic, [itex]\tau[/itex] is closer to 1.3 s than 1.2 s, but you obviously got the correct answer!)
     
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