Question

Автомобиль едет первую половину пути со скоростью 84 км/ч, а вторую половину пути — со скоростью 70 км/ч. Найди среднюю скорость автомобиля на всём пути. Ответ округли до целых. Средняя скорость автомобиля на всём пути — км/ч.

Answer 1

Ответ:

72км/ч

Объяснение:

Нам просто нужно узнать среднее арифметическое

(84+70):2=72

Answer 2

Calculation of Average Speed

To find the average speed of the car for the entire journey, we can use the formula:

Average Speed = Total Distance / Total Time

In this case, the car travels the first half of the distance at a speed of 84 km/h and the second half at a speed of 70 km/h. Since the distance covered in both halves is the same, we can assume that the total distance is twice the distance covered in one half.

Let's denote the distance covered in one half as d. Therefore, the total distance is 2d.

To calculate the total time, we need to find the time taken for each half of the journey and then add them together.

The time taken for the first half of the journey can be calculated using the formula:

Time = Distance / Speed

For the first half, the distance is d and the speed is 84 km/h. Therefore, the time taken for the first half is d / 84.

Similarly, the time taken for the second half of the journey can be calculated using the formula:

Time = Distance / Speed

For the second half, the distance is d and the speed is 70 km/h. Therefore, the time taken for the second half is d / 70.

The total time taken for the entire journey is the sum of the times taken for the first and second halves:

Total Time = (d / 84) + (d / 70)

Now, we can substitute the values of Total Distance and Total Time into the formula for Average Speed:

Average Speed = (2d) / [(d / 84) + (d / 70)]

To find the average speed, we can simplify the equation and solve for d:

Average Speed = (2 * 84 * 70) / (84 + 70)

Let's calculate the average speed using this formula.

Calculation:

Average Speed = (2 * 84 * 70) / (84 + 70)

Average Speed ≈ 76 km/h

Therefore, the average speed of the car for the entire journey is approximately 76 km/h.

Please note that the answer has been rounded to the nearest whole number as requested.