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Homework Help: Explosion with two Ice Skaters

  1. Mar 22, 2012 #1
    1. The problem statement, all variables and given/known data

    Two ice skaters stand at rest in the center of an ice rink. When they push off one another, the 60 kg skater acquires a speed of .61 m/s. If the speed of the other skater is .8m/s what is this skater's mass?

    2. Relevant equations

    explosion- pi=pf

    3. The attempt at a solution

    m2=17.43 but it said this was wrong

    but then i got a really big number which doesn't seem right
  2. jcsd
  3. Mar 22, 2012 #2


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    Staff: Mentor

    Recheck your formulas. What's the formula for the momentum of a moving body?
  4. Mar 22, 2012 #3
  5. Mar 22, 2012 #4


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    Staff: Mentor

    Is that a guess?
  6. Mar 22, 2012 #5
    so do i do m1v1=m2v2 instead of squaring the velocities
  7. Mar 22, 2012 #6
    got it! thanks
  8. Mar 22, 2012 #7


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    Homework Helper

    yes, that's right man. Its simply conservation of momentum.
  9. Mar 22, 2012 #8


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    Science Advisor

    There is NO "conservation of energy" (which is what you were trying to use first) because the "explosion" (push) adds energy to the system.
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