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Homework Help: Elastic 2-D Collisions without given masses?

  1. Dec 14, 2008 #1
    1. The problem statement, all variables and given/known data
    In a classic curing shot, the shot stone, traveling at 6.0m/s [E] hits a stationary stone. The target stone is propelled at a velocity of 2.0 m/s [East30degreesSouth] What is the velocity of the shot stone after the collision? (Assume the collision is fully elastic)

    2. Relevant equations
    V11 =((ΔmΔV)/ MT) + V2
    V21 = ((-2*M1*ΔV) / MT) + V2

    3. The attempt at a solution
    I don't know how to figure out this question without a mass
    Do I go through the solution and just sub in a value for m? The problem is that the result will be different if the curling stones have different masses...
    Last edited: Dec 14, 2008
  2. jcsd
  3. Dec 14, 2008 #2


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    Since the masses of the stones are the same, I would think it would cancel out.
  4. Dec 14, 2008 #3
    Thats just it, it doesn't say they are the same. It doesn't specify what the mass is of either of the stones..
  5. Dec 14, 2008 #4
    "a classic curing shot" so its the same mass.
  6. Dec 14, 2008 #5


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  7. Dec 14, 2008 #6
    Oh, I didn't realize that in a classic curling shot, they have the same mass... We've done examples in class where the rocks have the same mass, and some have different...
    Thanks for your help everyone :)
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