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Homework Help: Conservation of energy of ball with drag

  1. Jan 16, 2008 #1
    1. The problem statement, all variables and given/known data
    A .63 kg ball is thrown up with an initial speed of 14 m/s and reaches a maximum height of 8.1m. How much energy is dissipated by the air drag acting on the ball during the ascent?

    2. Relevant equations
    KE= 1/2MV^2

    3. The attempt at a solution
    I'm not very good at physics. I think I have to find the joules by plugging in the numbers accordingly in the equation, but I don't know what to do from there...

    KE = .5(.63)(14)^2 = 61.74

    The actual answer is -12 J >.<
  2. jcsd
  3. Jan 16, 2008 #2


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    Science Advisor
    Homework Helper

    Compare the change in kinetic energy with the change in potential energy. Which is mgh. The difference is the loss to friction.
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