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Homework Help: P=Fv what force represents

  1. Jul 1, 2008 #1
    In the equation P=Fv, I am unsure of what exactly the force reprents. Let's say that there is a car of mass 1000kg travelling at a constant velocity 30m/s, driven by an engine developing 25kW. Since F=P/v, F= 833.33N. However, this is clearly not the resultant force on the car - since the resultant force is 0N. Does this mean that resistive forces must be 833.33N? If so, please can someone explain why a force is needed for this motion? Also, if the power were to be increased, would the force increase, or the velocity increase?

  2. jcsd
  3. Jul 1, 2008 #2


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    Re: P=Fv

    You've already explained it. You've computed the force that the engine is applying to the car to overcome the friction force. So, yes, the friction force is 833.33N.
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