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Homework Help: How much work? Given speeds and mass

  1. Apr 5, 2008 #1
    1. The problem statement, all variables and given/known data
    How much work is done by an Olympic triathlete who accelerates herself on her bicycle (combined mass of 105kg) from 5m/s to 10m/s

    2. Relevant equations
    W = mg[tex]\Delta[/tex]d

    3. The attempt at a solution
    Tried solving for d, and plugging in.
  2. jcsd
  3. Apr 5, 2008 #2
    Your equation would apply if there was gravitational energy involved, but in this question there isn't. Work here is defined as W = Fd where F = ma.
  4. Apr 5, 2008 #3
    But still, how would I solve for d?
  5. Apr 5, 2008 #4
    Use kinematics to solve for a and d simultaneously.
  6. Apr 5, 2008 #5
    W = delta(KE)

    All you need to do is subtract her final kinetic energy from her initial kinetic energy to find the answer.
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