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Homework Help: Regarding another momentum problem

  1. Jan 17, 2006 #1
    a 4kg object travelling west a 25 m/s hots a 15 kg object at rest. the 4 kg object bounces eastward at 8 m/s. what is the speed and direction of the 15 kg object.

    i set it up at

    (m1)(v1)+(m2)(v2)= (mtotal)(vfinal)
    100/ 19 = x
    5.26 = x

    except i solvedfor the final v
    IM STUMPED anything on what i did wrong?:yuck:
  2. jcsd
  3. Jan 17, 2006 #2


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    Homework Helper
    Gold Member

    your problem here is your formula. You are using a formula where the two objects stick together after the collision. (Inelastic) instead of one where they bounce off.(elastic)
    Last edited: Jan 17, 2006
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