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Homework Help: Momentum - collision

  1. Jan 6, 2008 #1
    [SOLVED] Momentum - collision

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

    An object of mass 950kg travelling east collides with an object of mass 1900kg travelling north. The two objects then move off together at 16m/s in a direction of 24degrees east of north. Find their respective velocities prior to the collision.

    2. Relevant equations

    p = mv

    3. The attempt at a solution
    Momentum after collision = 2850 x 16 = 45600
    As momentum is a vector, then breaking it into its components we get:
    Object 1: 950 x v1 = (45600)cos24 ... v1=43.85m/s
    Object 2: 1900 x v2 = (45600)sin 24... v2=9.76m/s

    I thought this seemed simple enough, but apparently the answers are wrong... can anyone see where I might have made mistake, or am I just going about it the wrong way altogether?
  2. jcsd
  3. Jan 6, 2008 #2


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    Homework Helper

    you got the sin/cos mixed up.... 24 degrees "east of north" is pointing more north than east...
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