Question

Из двух городов навстречу друг другу одновременно вышли два поезда. Скорость первого - 85 км/ч, второго - 70 км/ч. Поезда встретились через 5ч. Найди расстояние между городами. Какое расстояние было между поездами за 2ч до встречи?

Answer 1

S-расстояние. V-cкорость

Answer 2

Problem Analysis

We have two trains traveling towards each other simultaneously. The speed of the first train is 85 km/h, and the speed of the second train is 70 km/h. The trains meet after 5 hours. We need to find the distance between the cities and the distance between the trains 2 hours before they meet.

Distance between the Cities

To find the distance between the cities, we can use the formula: distance = speed * time. Let's calculate the distance using the given information.

The speed of the first train is 85 km/h, and the speed of the second train is 70 km/h. The trains meet after 5 hours. Therefore, the distance between the cities can be calculated as follows:

Distance = (Speed of the first train + Speed of the second train) * Time Distance = (85 km/h + 70 km/h) * 5 hours

Let's calculate the distance using the given information.

Calculation

Distance = (85 km/h + 70 km/h) * 5 hours Distance = 155 km/h * 5 hours Distance = 775 km

Therefore, the distance between the cities is 775 km.

Distance between the Trains 2 Hours Before the Meeting

To find the distance between the trains 2 hours before they meet, we need to calculate the distance each train has traveled in 2 hours.

The speed of the first train is 85 km/h, and the speed of the second train is 70 km/h. We need to calculate the distance each train has traveled in 2 hours.

Distance traveled by the first train in 2 hours = Speed of the first train * Time Distance traveled by the first train in 2 hours = 85 km/h * 2 hours

Distance traveled by the second train in 2 hours = Speed of the second train * Time Distance traveled by the second train in 2 hours = 70 km/h * 2 hours

Let's calculate the distances using the given information.

Calculation

Distance traveled by the first train in 2 hours = 85 km/h * 2 hours Distance traveled by the first train in 2 hours = 170 km

Distance traveled by the second train in 2 hours = 70 km/h * 2 hours Distance traveled by the second train in 2 hours = 140 km

Therefore, the distance between the trains 2 hours before they meet is 170 km.

Summary

- The distance between the cities is 775 km. - The distance between the trains 2 hours before they meet is 170 km.

Please let me know if you need any further clarification.