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Homework Help: Work problem 1

  1. Mar 4, 2014 #1
    1. The problem statement, all variables and given/known data

    Gasoline has an energy content of 9.38 × 10^5 J/oz. If a car,
    with a mass of 1500 kg, is accelerated to a speed of 29.1
    m/s, how much gas is consumed by the engine, assuming
    40% efficiency?

    2. Relevant equations
    w= ΔKE

    3. The attempt at a solution
    So I started by multiplying the energy content of gasoline by .4 so I believe I could just treat it was being 100 percent efficient after that.
    I then calculated the KE the car had at the end of it's acceleration. 1/2*(1500kg)*(29.1 m/s)^2 = 635107.5 J. I then divided this by the amount of energy a car uses per oz of gasoline which was .4 * 9.38*10^5 J/oz to get the oz's. Which was 1.69.
    Is this all correct?

    Thank you to anyone for their time.
  2. jcsd
  3. Mar 4, 2014 #2

    rude man

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    Homework Helper
    Gold Member

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