Question

Со станции одновременно в противоположных направлениях вышли две электрички. Скорость первой электрички 70 км/ч, скорость второй - 90 км/ч. Какое расстояние будет между электричками через 5 часов? Составить и решить обратную задачу.

Answer 1

1)(90+70)*5=800км - проедут за 5 часов.
Обратная задача -
Со станции одновременно вышли два поезда,которые двигались в противополжных направлениях,через 4 часов между ними было расстояние 360 км. Найди скорость обоих поездов,если второй поезд ехал в 2 раза быстрее другого.
360:4=90км/ч - скорость двух поездов
90:2 = 45км/ч
45+15 = 60км/ч - скорость 2 поезда
90 - 60 = 30км/ч  - скорость 1 поезда

Answer 2

Problem Analysis

We are given that two trains start simultaneously from a station in opposite directions. The first train has a speed of 70 km/h, and the second train has a speed of 90 km/h. We need to find the distance between the trains after 5 hours.

Solution

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

Let's calculate the distance traveled by each train after 5 hours.

For the first train: - Speed = 70 km/h - Time = 5 hours - Distance = 70 km/h × 5 hours = 350 km

For the second train: - Speed = 90 km/h - Time = 5 hours - Distance = 90 km/h × 5 hours = 450 km

Now, let's find the total distance between the two trains. Since they are moving in opposite directions, we can add their distances together.

Total distance = Distance of first train + Distance of second train Total distance = 350 km + 450 km = 800 km

Therefore, the distance between the two trains after 5 hours is 800 km.

Answer

The distance between the two trains after 5 hours is 800 km.

Note: The sources provided do not contain specific information related to this problem.