Question

Тепловой двигатель совершил полезную работу 23000Дж и израсходовал при этом 2кг бензина. Найти КПД теплового двигателя.

Answer 1

ДАНО: А полезная 23000
m: 2 кг 
q : 4.6*10^7 
решение : кпд = А полезное / Q1 
Q1 = mq
Q1= 2* (4.6*10^7)= 96000000
КПД = 23000:96000000*100
= 0.025%

Answer 2

Calculation of Efficiency of a Heat Engine

To find the efficiency of a heat engine, we can use the formula:

Efficiency (η) = Useful work output / Energy input

In this case, the useful work output is given as 23,000 J (joules), and the energy input is the energy content of the gasoline consumed, which is 2 kg.

Let's calculate the efficiency:

Efficiency (η) = 23,000 J / (2 kg * energy content of gasoline)

To proceed further, we need to know the energy content of gasoline. The energy content of gasoline can vary, but for this calculation, we will assume an average value of 44 MJ/kg (megajoules per kilogram).

Substituting the values into the formula:

Efficiency (η) = 23,000 J / (2 kg * 44 MJ/kg)

Converting the energy content of gasoline from megajoules to joules:

Efficiency (η) = 23,000 J / (2 kg * 44,000,000 J/kg)

Simplifying the expression:

Efficiency (η) = 23,000 J / 88,000,000 J

Calculating the efficiency:

Efficiency (η) ≈ 0.000261

Therefore, the efficiency of the heat engine is approximately 0.000261, or 0.0261%.

Please note that this is a simplified calculation and does not take into account various factors that can affect the efficiency of a real heat engine, such as friction, heat losses, and other inefficiencies.

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