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Homework Help: Max engine Power Problem

  1. Apr 27, 2014 #1
    1. The problem statement, all variables and given/known data
    An auto manufacturer reports that the maximum power delivered by the engine of a car of mass 1230 kg is 92.4 kW. Find the minimum time in which the car could accelerate from rest to 29.1 m/s. In a test the time to do this is found to be 12.3 s. Account for the difference in this time.

    2. Relevant equations
    P = W/t
    Work-KE theorem

    3. The attempt at a solution
    t = [itex]\frac{W}{P}[/itex]
    = [itex]\frac{.5(1230)(29.1)^{2}}{92.4(10^{3})}[/itex]
    = 5.64s

    The difference in time is due to not accounting for friction force.
  2. jcsd
  3. Apr 28, 2014 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    Well done: did you have a question about this problem?
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