Question

Автомобиль прошел расстояние от а до в , со скоростью 36 километров в час , а обратно со скоростью 54 километров час, какова средняя скорость автомобиля?

Answer 1

2AB /Vcp  = AB/36 +AB/54
2 /Vcp  = 1/36 +1/54
2 /Vcp  = 5/108
Vcp = 2*108/5 =43,2  км/ч

Answer 2

Средняя скорость 45 км/ч

Answer 3

Calculation of Average Speed

To calculate the average speed of the car, we can use the formula:

Average Speed = Total Distance / Total Time

In this case, the car traveled from point A to point B at a speed of 36 kilometers per hour, and then returned from point B to point A at a speed of 54 kilometers per hour.

Since the distance traveled in both directions is the same, we can assume that the total distance is twice the distance from point A to point B.

Let's assume the distance from point A to point B is d kilometers.

The time taken to travel from point A to point B at a speed of 36 kilometers per hour is d / 36 hours.

The time taken to travel from point B to point A at a speed of 54 kilometers per hour is d / 54 hours.

The total time taken for the round trip is (d / 36) + (d / 54) hours.

Therefore, the average speed of the car can be calculated as:

Average Speed = (2d) / [(d / 36) + (d / 54)] kilometers per hour

Simplifying the expression:

Average Speed = (2d) / [(3d + 2d) / (36 * 54)] kilometers per hour

Average Speed = (2d) / [(5d) / (36 * 54)] kilometers per hour

Average Speed = (2d * 36 * 54) / (5d) kilometers per hour

Average Speed = (2 * 36 * 54) / 5 kilometers per hour

Average Speed = 777.6 kilometers per hour

Therefore, the average speed of the car is 777.6 kilometers per hour.