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Kinetic energy help

  1. Sep 10, 2008 #1
    1. The problem statement, all variables and given/known data
    A 2kg sinker is thrown with a vertical velocity of 10m/s from a bridge into a river 12m below. What is the kinetic energy of the sinker when it hits the river??

    Answer is 3.4*10^2 J

    2. Relevant equations

    KE = 1/2mv^2

    3. The attempt at a solution
    tried substituting directly into KE = 1/2mv^2 but obviously not write ant help would be appreciated.
  2. jcsd
  3. Sep 10, 2008 #2


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    Staff Emeritus
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    Gold Member

    Okay, so when the 'sinker' is thrown you've worked out that it has kinetic energy, but is that the only type of energy it has?
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