Question

7. Автомобіль на шляху 110 км витратив 6,9 кг бензину. Середня потужність, яку розвивав двигун, дорівнювала 15 кВт, а середня швидкість руху 72км/год. Знайти ККД двигуна. ​

Answer 1

Ответ:

Принцип работы двигателя внутреннего сгорания основан на эффекте теплового расширения газов, возникающего при сгорании топливно-воздушной смеси и обеспечивающего перемещение поршня в цилиндре. Работа поршневого ДВС осуществляется циклически

Answer 2

To find the efficiency of the engine, we can use the formula for efficiency (η):

η = (Useful output energy / Input energy) * 100%

In this case, the useful output energy is the work done by the engine, which can be calculated using the power (P) and time (t):

Useful output energy = P * t

The input energy is the energy provided by the fuel, which can be calculated using the amount of fuel consumed (m) and the energy content of the fuel (E):

Input energy = m * E

To find the efficiency, we need to calculate the useful output energy and the input energy.

Given: Distance traveled (d) = 110 km Fuel consumed (m) = 6.9 kg Power (P) = 15 kW Average speed (v) = 72 km/h

Calculating the useful output energy:

The work done by the engine can be calculated using the formula:

Useful output energy = Power * Time

To find the time, we can use the formula:

Time = Distance / Speed

Substituting the given values:

Time = 110 km / 72 km/h

Calculating the time:

Time = 1.53 hours

Now, we can calculate the useful output energy:

Useful output energy = 15 kW * 1.53 hours

Calculating the useful output energy:

Useful output energy = 22.95 kWh

Calculating the input energy:

The input energy can be calculated using the formula:

Input energy = Fuel consumed * Energy content of fuel

To find the energy content of the fuel, we need to know the specific energy of the fuel. Unfortunately, the specific energy of the fuel is not provided in the question. Therefore, we cannot calculate the input energy or the efficiency of the engine without this information.

Please provide the specific energy of the fuel in order to calculate the efficiency of the engine.