Question

ДОПОМОЖІТЬ ПУДЬЛАСКА У МЕНЕ ПО ФІЗИКЕ ДАЮ 100 БАЛОВ ТЕМА:ТЕПЛОВІ ЯВИЩА , 8 КЛАС Задача:Тепловий двигун працює на бензині і має ККД 25 % . Яку корисну роботу виконає двигун, якщо в ньому згорить 5 кг бензину ?​

Answer 1

Дано: КПД=25%=0,25; m=5 кг; Аполезн - ?

---------------------

КПД=Аполезн / Q

Аполезн=Q*КПД=q*m*0,25

Аполезн=4,6*10⁷ * 5 * 0,25=5,75*10⁷=57,5*10⁶Дж=57,5 МДж.

Answer 2

The Efficiency of a Heat Engine

To solve this problem, we need to use the formula for the efficiency of a heat engine. The efficiency (η) of a heat engine is defined as the ratio of the useful work output (W) to the heat input (Q) into the engine. Mathematically, it can be expressed as:

η = W / Q

In this case, we are given that the efficiency (η) of the heat engine is 25% or 0.25. We need to find the useful work output (W) when 5 kg of gasoline is burned in the engine.

Calculating the Useful Work Output

To calculate the useful work output, we need to know the heat input (Q) into the engine. The heat input can be calculated using the formula:

Q = m * c * ΔT

Where: - m is the mass of the gasoline burned (5 kg in this case) - c is the specific heat capacity of gasoline (which we will assume to be constant) - ΔT is the change in temperature of the gasoline during combustion

Unfortunately, the specific heat capacity of gasoline is not provided in the question. However, we can assume that the change in temperature (ΔT) is significant enough to produce a useful work output.

Conclusion

In conclusion, we are unable to calculate the useful work output of the heat engine without knowing the specific heat capacity of gasoline and the change in temperature during combustion. If you have any additional information or if there are any other aspects of the problem you would like me to address, please let me know.