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Homework Help: Conservation of energy and conservation of momentum

  1. Mar 12, 2006 #1
    Using both cinservation of energy and conservation of momentum, show that the spring constant k is given by k=2mg/H[1+mg/(m+M)H]

    I thought that this would go easier if I rewrote the expression for kinetic energy in terms of momentum, but I cant exactly get around figuring the change in momentum to build an equation. would (m1v1/2) be correct?
     
  2. jcsd
  3. Mar 12, 2006 #2

    Hootenanny

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    Do you have defintions for your symbols?
     
  4. Mar 12, 2006 #3
    as in initial mass and initial velocity?
     
  5. Mar 12, 2006 #4
    "Initial mass?" :surprised: Perhaps you'd better tell us what the question is.

    -Dan
     
  6. Mar 12, 2006 #5

    Hootenanny

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    Hmm, a mass spring system oscillating at close to the speed of light. I've never done relativistic effects with SHM before...could be interesting...:surprised
     
  7. Mar 12, 2006 #6
    It seems I have taken a wrong approach. I need to show that the spring constant k can be given by 2mg/H[1+mg/(m+M)H] using thr conservation of energy and momentum.
     
  8. Mar 12, 2006 #7

    Hootenanny

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    Does the question not give you any definitions for the symbols used?
     
  9. Mar 13, 2006 #8
    I worked it out. No matter
     
  10. Mar 13, 2006 #9
    :mad: Then at least have the decency to tell us! You've got ME curious, anyway.

    -Dan
     
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