Question

Два автомобиля выехали одновременно из городов А и В навстречу друг другу Через 5 ч. они встретились и, не останавливаясь, продолжили движение. Первый автомобиль прибыл в А на 5 ч 20 мин раньше, чем второй в город В. Найдите скорость второго автомобиля (км/ч), если расстояние между городами составляет 720 км.

Answer 1

Ответ: 1) 720÷5=144(км) второй город

Ответ: 144 км второго автомобиля.

Пошаговое объяснение:

Answer 2

Problem Analysis

We are given that two cars, A and B, start simultaneously from two different cities and travel towards each other. After 5 hours, they meet and continue their journey without stopping. The first car arrives at city A 5 hours and 20 minutes earlier than the second car arrives at city B. We need to find the speed of the second car if the distance between the cities is 720 km.

Solution

Let's assume the speed of the first car is v1 km/h and the speed of the second car is v2 km/h.

We know that the time taken by both cars to meet is 5 hours. Therefore, the distance traveled by the first car in 5 hours is 5 * v1 km, and the distance traveled by the second car in 5 hours is 5 * v2 km.

We also know that the first car arrives at city A 5 hours and 20 minutes earlier than the second car arrives at city B. This means that the second car takes an additional 5 hours and 20 minutes to cover the remaining distance between the meeting point and city B.

Let's calculate the time taken by the second car to cover the remaining distance: - The total distance between the cities is 720 km. - The distance traveled by both cars in 5 hours is 5 * (v1 + v2) km. - Therefore, the remaining distance for the second car is 720 - 5 * (v1 + v2) km.

The second car takes 5 hours and 20 minutes to cover this remaining distance. Let's convert this time to hours: - 20 minutes is equal to 20 / 60 = 1/3 hours. - Therefore, the time taken by the second car to cover the remaining distance is 5 + 1/3 = 16/3 hours.

Now, we can set up an equation to solve for the speed of the second car: distance = speed * time - The remaining distance for the second car is 720 - 5 * (v1 + v2) km. - The time taken by the second car to cover the remaining distance is 16/3 hours. - Therefore, the equation becomes: 720 - 5 * (v1 + v2) = v2 * (16/3).

Let's solve this equation to find the speed of the second car.

Calculation

We can simplify the equation as follows:

720 - 5 * (v1 + v2) = v2 * (16/3)

Multiplying both sides by 3 to eliminate the fraction:

2160 - 15 * (v1 + v2) = 16 * v2

Expanding the brackets:

2160 - 15 * v1 - 15 * v2 = 16 * v2

Moving all the terms involving v2 to one side:

16 * v2 + 15 * v2 = 2160 - 15 * v1

Combining like terms:

31 * v2 = 2160 - 15 * v1

Dividing both sides by 31 to solve for v2:

v2 = (2160 - 15 * v1) / 31

Now, we can substitute the value of v1 into this equation to find the speed of the second car.

Answer

The speed of the second car is (2160 - 15 * v1) / 31 km/h.

Please note that we need the value of v1 to calculate the speed of the second car. Unfortunately, the given information does not provide the value of v1. If you have the value of v1, please provide it, and I will be able to calculate the speed of the second car for you.