Question

Первую часть пути автомобиль проехал за 4 ч, а вто- рую за 3 ч. Первую часть пути он ехал с некоторой постоянной скоростью, а вторую часть пути со ско- ростью, на 10 км/ч большей. Всего он проехал 520 км. какова скорость автомобиля на первом участке пути?

Answer 1

Problem Analysis

We are given that a car traveled the first part of the journey in 4 hours and the second part in 3 hours. The car traveled the first part at a certain constant speed and the second part at a speed that is 10 km/h faster. The total distance traveled is 520 km. We need to find the speed of the car during the first part of the journey.

Solution

Let's assume the speed of the car during the first part of the journey is x km/h. Since the car traveled the first part of the journey in 4 hours, the distance covered during the first part is 4x km.

During the second part of the journey, the car traveled at a speed that is 10 km/h faster than the first part. So the speed during the second part is x + 10 km/h. The time taken for the second part is 3 hours, so the distance covered during the second part is 3(x + 10) km.

The total distance traveled is given as 520 km. Therefore, we can write the equation:

4x + 3(x + 10) = 520

Simplifying the equation:

4x + 3x + 30 = 520

7x + 30 = 520

7x = 490

x = 70

Therefore, the speed of the car during the first part of the journey is 70 km/h.

Answer

The speed of the car during the first part of the journey is 70 km/h.