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Help is this right!

  1. Mar 7, 2005 #1
    Billie (35 kg) and Joannie (50 kg), both with brand new roller blades, are at rest facing each other in the parking lot. They push off each other and move in opposite directions, Joannie moving at a constant speed of 14 ft/s. What speed is Billie moving?

    Joanie: convert ft/s to meters 14ftx12 in=168in. 168/39.37=4.27 meters
    a=F/m 4.27m=F/50kg
    F=213.5 N

    Billie: a=213.5 kgm/35kg

    6.1m x 39.37 in= 240in
    240in/12in= 20ft/s
  2. jcsd
  3. Mar 7, 2005 #2


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    Science Advisor

    Use Conservation of Momentum to obtain:
    {Mass of B}*{Speed of B} = {Mass of J}*{Speed of J}

    Last edited: Mar 7, 2005
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