Question

Решите задачу. из двух городов A и B расстояние между которыми 390 км навстречу друг другу одновременно выехали два автомобиля. скорость первого автомобиля равна 60 км/ч а второго 70 км/ч. через сколько часов после встречи первый автомобиль прибудет в пункт В?

Answer 1

1) 60 + 70 = 130 (км/ч) - скорость сближения двух автомобилей

2) 390 : 130 = 3 (ч) - через 3 часа автомобили встретятся

3) 390 : 60 = 6,5 (ч) - время прохождения первого автомобиля от А до В

4) 6,5 - 3 = 3,5 (ч) - время, через которое первый автомобиль прибудет в пункт В после встречи со вторым автомобилем

Answer 2

Problem Analysis

We have two cars traveling towards each other from cities A and B, with a distance of 390 km between them. The first car is traveling at a speed of 60 km/h, and the second car is traveling at a speed of 70 km/h. We need to determine how many hours it will take for the first car to reach city B after the meeting point.

Solution

To solve this problem, we can use the formula: time = distance / speed.

Let's calculate the time it takes for the two cars to meet each other: - The total distance traveled by both cars is 390 km. - The combined speed of the two cars is 60 km/h + 70 km/h = 130 km/h.

Using the formula, we can calculate the time it takes for the two cars to meet: time = distance / speed = 390 km / 130 km/h = 3 hours.

Since the two cars meet after 3 hours, we need to determine how much time it will take for the first car to reach city B after the meeting point. Since the first car is traveling at a speed of 60 km/h, we can calculate the remaining distance from the meeting point to city B: - The remaining distance is 390 km - (60 km/h * 3 hours) = 390 km - 180 km = 210 km.

Now, we can calculate the time it takes for the first car to reach city B: time = distance / speed = 210 km / 60 km/h = 3.5 hours.

Therefore, it will take the first car 3.5 hours to reach city B after the meeting point.

Answer

The first car will arrive at city B 3.5 hours after the meeting point.