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Homework Help: Momentum and stopping distance

  1. Jul 13, 2009 #1
    1. The problem statement, all variables and given/known data

    Two objects have different masses, but the same momenta. If you stop them with the same retarding force, which one will stop in the shorter distance. The heavier or lighter one? Or will both have the same distance?

    2. Relevant equations

    3. The attempt at a solution

    Wouldn't the heavier one take more force to stop it, thus leading to a greater distance? However, the correct answer is that the heavier one will stop in the shorter distance. Explain, thanks!
  2. jcsd
  3. Jul 13, 2009 #2


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    Science Advisor

    What's the equation which relates momentum to mass and velocity?
  4. Jul 13, 2009 #3


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    Homework Helper

    retarding force X distance moved = change in kinetic energy.
    Can you find the relation between momentum and kinetic energy?
  5. Jul 13, 2009 #4

    change in KE=fd



    So basically, the greater the mass, the smaller the KE. And the smaller the KE, the smaller the distance. ok...thanks.
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