Question

107. Между городами А и В по железной дороге 710 км. Из А в в вы шел поезд со скоростью 75 км/ч. Через 2 ч навстречу ему из в в А вышел другой поезд со скоростью 65 км/ч. Через сколько часов после выхода второго поезда они встретятся? (условие)​

Answer 1

Ответ:

1)75*2=150 км прошёл первый поезд до выхода второго

2)710-150=560 км осталось пройти поездам до встречи

3)75+65=140 км/час скорость сближения поездов

4)560:140=4 часа

Пошаговое объяснение:

Answer 2

Ответ:

1)75*2=150км/ч

2)710-150=560 км

3)75+65=140 км

4)560:140=4

Ответ:4

Answer 3

Problem Analysis

We are given that the distance between cities A and B is 710 km. A train departs from city A towards city B with a speed of 75 km/h. After 2 hours, another train departs from city B towards city A with a speed of 65 km/h. We need to determine how many hours it will take for the two trains to meet.

Solution

To solve this problem, we can use the concept of relative speed. The relative speed of the two trains is the sum of their individual speeds. In this case, the relative speed is 75 km/h + 65 km/h = 140 km/h.

We can calculate the time it takes for the two trains to meet by dividing the distance between the two cities by the relative speed of the trains:

Time = Distance / Relative Speed

Substituting the given values, we have:

Time = 710 km / 140 km/h

Calculating this, we find:

Time = 5.07 hours

Therefore, the two trains will meet approximately 5.07 hours after the second train departs from city B.

Answer

The two trains will meet approximately 5.07 hours after the second train departs from city B.