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Homework Help: Energy to a 40% efficient engine

  1. Dec 16, 2008 #1
    1. The problem statement, all variables and given/known data

    A 40%-efficient car engine accelerates the 1200 kg car from rest to 18 m/s.
    How much energy is transferred to the engine by burning gasoline?

    any help is appreciated
     
  2. jcsd
  3. Dec 16, 2008 #2

    cepheid

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    1. How much work is done by the engine?
    2. Is all of the engine's energy being used to do that work? No, because the engine is not 100% efficient.
    3. So how much energy must be released by burning in order for the engine to be able to do the amount of work calculated in (1) after 60% of said energy is thrown away?
     
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