Question

Двигун автомобіля за 30хв використав 9 кг бензину яку потужність він розвивав якщо ККД 33%​

Answer 1

Смотри вниз:

Скорость равна V = 72000/3600 = 20 м/с.

Время движения автомобиля на пути в 100 км T = S/V = 100*1000/20 =

= 5000 с.

Энергия (работа) от сгорания топлива A = 8*44*10⁶ = 3,52*10⁸ Дж.

Общая мощность N = A / T = 3,52*10⁸ / 5000 = 7,01*10⁴ Вт = 70,4 кВт, а полезная составит Nп = N*КПД = 70,4 * 0,4 = 28,16 кВт.

Сила тяги составит F = A / S = 28160 / 20 = 1408 H.

Answer 2

Calculating the Engine Power

To calculate the power developed by the engine, we can use the formula:

Power = Energy Output / Time

In this case, the energy output is the energy released by burning the gasoline, and the time is the duration of the engine operation.

Energy Released by Burning Gasoline

The energy released by burning gasoline can be calculated using the formula:

Energy = Mass of Fuel × Energy Content of Fuel

Given that 9 kg of gasoline was used and the efficiency (ККД) is 33%, we can calculate the energy released.

Calculating Energy Released

The energy content of gasoline is approximately 34.2 MJ/liter, and the density of gasoline is around 0.74 kg/liter. Using these values, we can calculate the energy released by 9 kg of gasoline.

Energy Content of Gasoline = 34.2 MJ/liter Density of Gasoline = 0.74 kg/liter

Now, let's calculate the energy released by 9 kg of gasoline.

Energy Released = Mass of Fuel × Energy Content of Fuel

Energy Released = 9 kg × (34.2 MJ/liter / 0.74 kg/liter)

Energy Released ≈ 415.22 MJ

Calculating Power Developed by the Engine

Now that we have the energy released, we can calculate the power developed by the engine using the formula:

Power = Energy Output / Time

Given that the engine operated for 30 minutes (0.5 hours), we can calculate the power developed.

Power = 415.22 MJ / 0.5 hours

Power ≈ 830.44 MW

So, if the engine operated for 30 minutes and used 9 kg of gasoline with an efficiency of 33%, it developed a power of approximately 830.44 MW.