Question

9. Автомобіль рухався зі швидкістю 90 км/год протягом 40 хв. ККД двигуна дорівнює 30 %. Визнач масу бензину, яку використав двигун автомобіля за час руху, якщо сила тяги двигуна становить 40 кН. ПОМОГИТЕ, ПОЖАЛУЙСТА, ДАМ 100 БАЛОВ И ЛУЧШИЙ ОТВЕТ!​

Answer 1

Відповідь: 173,9 кг

Пояснення:

Answer 2

Calculation of the Mass of Gasoline Used by the Engine

To calculate the mass of gasoline used by the engine during the given time of travel, we need to consider the fuel efficiency of the engine, which is given as 30%. We also have the speed of the car, which is 90 km/h, and the duration of travel, which is 40 minutes.

First, let's convert the speed from kilometers per hour to meters per second. We know that 1 kilometer is equal to 1000 meters, and 1 hour is equal to 3600 seconds. Therefore, the speed in meters per second is:

Speed = 90 km/h * (1000 m/km) / (3600 s/h) = 25 m/s.

Next, we need to calculate the force exerted by the engine, which is given as 40 kN (kilonewtons). The force exerted by the engine is equal to the product of mass and acceleration. Since the car is moving at a constant speed, the acceleration is zero. Therefore, the force exerted by the engine is equal to the force of friction opposing the motion. In this case, the force of friction is equal to the product of the mass of the car and the acceleration due to friction.

To calculate the mass of the car, we can use Newton's second law of motion, which states that force is equal to mass times acceleration. Rearranging the equation, we have:

Mass = Force / Acceleration.

Since the acceleration is zero, the mass of the car is undefined. However, we can assume that the mass of the car is not relevant to the calculation of the mass of gasoline used by the engine.

Now, let's calculate the mass of gasoline used by the engine. The work done by the engine is equal to the force exerted by the engine multiplied by the distance traveled. The work done by the engine is also equal to the energy output of the engine, which is equal to the energy content of the gasoline used.

The energy content of gasoline is typically measured in joules per liter. To calculate the mass of gasoline used, we need to convert the energy content from joules per liter to joules per kilogram. Since the density of gasoline is approximately 0.75 kg/liter, we can use this value to convert the energy content.

Now, let's calculate the mass of gasoline used by the engine. The work done by the engine is equal to the force exerted by the engine multiplied by the distance traveled. The work done by the engine is also equal to the energy output of the engine, which is equal to the energy content of the gasoline used.

The energy content of gasoline is typically measured in joules per liter. To calculate the mass of gasoline used, we need to convert the energy content from joules per liter to joules per kilogram. Since the density of gasoline is approximately 0.75 kg/liter, we can use this value to convert the energy content.

The energy content of gasoline is typically around 32 MJ/L (megajoules per liter) To convert this to joules per kilogram, we divide by the density of gasoline:

Energy content of gasoline = 32 MJ/L * (1 L / 0.75 kg) = 42.67 MJ/kg.

Now, we can calculate the mass of gasoline used by the engine. The work done by the engine is equal to the force exerted by the engine multiplied by the distance traveled. The distance traveled is equal to the speed of the car multiplied by the duration of travel:

Distance = Speed * Time = 25 m/s * 40 min * (60 s/min) = 60000 m.

The work done by the engine is equal to the force exerted by the engine multiplied by the distance traveled:

Work = Force * Distance = 40 kN * 60000 m = 2400000 kNm = 2400000 J.

Finally, we can calculate the mass of gasoline used by the engine using the energy content of gasoline:

Mass of gasoline used = Work / Energy content of gasoline = 2400000 J / 42.67 MJ/kg = 0.056 kg.

Therefore, the mass of gasoline used by the engine during the given time of travel is approximately 0.056 kg.

Please note that this calculation assumes ideal conditions and may not reflect the exact amount of gasoline used in real-world scenarios. Factors such as engine efficiency, driving conditions, and variations in fuel composition can affect the actual fuel consumption of a vehicle.