If a gasoline engine has an efficiency of 21 percent and loses 780 J to the cooling system and exhaust during each cycle, how much work is done by the engine?

Is it 3709.5???

Chemical energy in (as fuel and oxygen) = Work out + Heat out
21% is the ratio of Work out to Chemical energy in. That means that 79% is the ratio (Heat)out/(Chemical E)in.

The ratio of (work)out to (heat)out is 21/79

W/Q = .21/.79 = 21/79 = W/780 J

W = (780/79)*21 = ?

  1. 👍 0
  2. 👎 2
  3. 👁 2,428
  1. 207.34

    1. 👍 0
    2. 👎 0
  2. 1. Work done = Energy output(Eo).
    Eff. = Eo/Ein = Eo/(Eo+780) = 0.21
    Eo = 0.21(Eo+780)
    Eo = 0.21Eo + 163.8
    0.79Eo = 163.8
    Eo = 207.3 J.

    1. 👍 0
    2. 👎 0
  3. i don't understand henry's equation, maybe use Qh and Qc next time?

    1. 👍 1
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions


    Given: The energy equivalent of one gallon of gasoline is 1.3 × 108 J. A compact car has a mass of 847 kg, and its efficiency is rated at 18.1%. (That is, 18.1% of the input power available is delivered to the wheels.) Find the

  2. physics

    A car's internal combustion engine can be modeled as a heat engine operating between a combustion temperature of 1500∘C and an air temperature of 20∘C with 30% of the Carnot efficiency. The heat of combustion of gasoline is 47


    Converting sunlight to electricity with solar cells has an efficiency of 15%. It's possible to achieve a higher efficiency (though currently at higher cost) by using concentrated sunlight as the hot reservoir of a heat engine.

  4. physics

    A 40%-efficient car engine accelerates the 1300 kg car from rest to 20 m/s How much energy is transferred to the engine by burning gasoline? .

  1. physics......PLEASE HELP!!

    A steam engine absorbs 1.98*10^5 J and expels 1.49*10^5 J in each cycle. Assume that all of the remaining energy is used to do work. a. What is the engine's efficiency? b. How much work is done in each cycle? If a gasoline engine

  2. physics.

    Heat engine X takes four times more energy by heat from the hot reservoir than heat engine Y. Engine X delivers two times more work, and it reject seven times more energy by heat to the cold reservoir than heat engine Y. Find the

  3. Physics

    In each cycle of its operation, a heat engine expels 2400 J of energy and performs 1800 J of mechanical work. (a) How much thermal energy must be added to the engine in each cycle? (b) Find the thermal efficiency of the engine.

  4. physics

    an engine pumps of 100 kg of water through a height of 10m in 5 second. Given that the efficiency of engine is 60%. If g=10m/s^2 the power of engine is

  1. physics

    A heat engine receives 7.0 x 10^3 J of heat and loses 3.0 x 10^3 J in each cycle. What is the efficiency? 1-30% 2-43% 3-57% 4-70% 5-100%

  2. engineering science

    A ramjet is to propel an aircraft at Mach 3 at high altitude where the ambient pressure is 8.5 kPaand the ambient temperature T-node is 220 K. The turbine inlet temperature T is 2540 K. If all components of the engine are ideal -

  3. Physics

    A heat engine exhausts 3 000 J of heat while performing 1 500 J of useful work. What is the efficiency of the engine?

  4. Chemistry

    In Europe, gasoline efficiency is measured in km/L . If your car's gas mileage is 28.0 mi/gal, how many liters of gasoline would you need to buy to complete a 142-km trip in Europe? Use the following conversions: 1km=(0.6214mi)

You can view more similar questions or ask a new question.