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Homework Help: Maximum travelling distance of car from 1 L of fuel

  1. Apr 17, 2010 #1
    Sorry 1 and 2 aren't filled in very well but I have absolutely no idea what to do for this question. My brain wasn't designed for physics :(

    1. The problem statement, all variables and given/known data

    Question: A car travelling at 60.0 km/h has a total retarding force of 1500 N due to air resistance. If 1.00 L of petrol can release 40 000 000 J of energy, how many kilometres can the car travel at 60.0 km/h on 1.00 L of fuel (assume that the engine is 5% efficient)?

    2. Relevant equations

    I really have no idea, but making a rough guess. . .

    s=ut+0.5at^2

    or

    v^2=u^2 +2as

    3. The attempt at a solution

    ?????

    Really, I have no idea where to start.

    Any help would be greatly appreciated!
     
  2. jcsd
  3. Apr 17, 2010 #2
    All the energy that the engine gets from the petrol goes into opposing the work done by the retarding force.
     
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