Question

Проехав за час половину пути ,машинист увеличил скорость электропоезда на 40км/ч и поэтому прошёл вторую половину пути за 45 минут.С какой скоростью шёл электропоезд первую половину пути?

Answer 1

Пусть 1ю половину пути он прошёл со скорость х тогда вторую х+40 Уравнение: х=(х+40)*3/4 х-3/4х=30 1/4х=30 х=30/0.25 х=120 км-путь который прошёл машинист 120/1- это скорость в первой половине, вроде так

Answer 2

Calculation of the Train's Speed

To determine the speed at which the train traveled during the first half of the journey, we can use the information provided. Let's break down the given information:

- The train traveled half of the distance in one hour. - The train increased its speed by 40 km/h. - The train covered the second half of the distance in 45 minutes.

To find the speed of the train during the first half of the journey, we need to calculate the distance traveled during the second half of the journey. We can then subtract this distance from the total distance to find the distance traveled during the first half.

Let's assume the total distance of the journey is D km.

The train traveled half of the distance in one hour, so the distance covered during the first half is D/2 km.

The train increased its speed by 40 km/h, so the speed during the second half of the journey is x + 40 km/h, where x is the speed during the first half of the journey.

The train covered the second half of the distance in 45 minutes, which is equal to 45/60 = 0.75 hours. Therefore, the distance covered during the second half is (x + 40) * 0.75 km.

The total distance of the journey is the sum of the distances covered during the first and second halves:

D = D/2 + (x + 40) * 0.75

Now we can solve this equation to find the value of x, which represents the speed of the train during the first half of the journey.

Let's solve the equation:

D = D/2 + (x + 40) * 0.75

Simplifying the equation:

D/2 = (x + 40) * 0.75

Multiplying both sides by 2:

D = 2 * (x + 40) * 0.75

Dividing both sides by 0.75:

D/0.75 = 2 * (x + 40)

Simplifying further:

D/0.75 = 2x + 80

Subtracting 80 from both sides:

D/0.75 - 80 = 2x

Dividing both sides by 2:

x = (D/0.75 - 80) / 2

Now we have the formula to calculate the speed of the train during the first half of the journey. We just need to substitute the value of D with the actual distance.

Unfortunately, the given question does not provide the value of the total distance of the journey. Without this information, we cannot calculate the exact speed of the train during the first half of the journey.

If you have the value of the total distance, please provide it, and I will be happy to help you with the calculation.