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Collision of marbles and stones

  1. Oct 12, 2010 #1
    1. Question: A 100g stone rests on a fricionless horizontal surface. A marble of mass 40g, travelling horizontantally at 30m/s strikes the stone and rebunds horizontally at right angles to its original direction wiht a speed of 20m/s. What is the velocity (magnitude and direction) of the stone after it has been struck? Can you see anything wrong with this question?

    i think the relevant equations are: p = final momentum - initial momentum which is here 1,2 + 0,8 = 2 kgm/s

    and to look for the velocity after it has been struck i used the formula p= 2kgm/s= (mA+mB).v so the v= 2:0,14 = 14,29, but think thats not the right formula and i dont know whats wrong with this question, i think its the "at right angles" bit, that confuses me the most... can someone pleaase help? :)

    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
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