Question

россияне между двумя городами 720 км. Из этих городов навстречу друг друга вышли аднавременно два поезда со скоростями 38км/ч и 52 км/ч. Через сколько часов поезда встретятся?

Answer 1

S расстояние
V скорость
t время
1)38+52=90 км/ч-V первого и V второго
2)720÷90=8 ч-t

Answer 2

1) 52-38=14 ( км/ч ) Cкорость сближения 

Answer 3

Problem Analysis

We are given that two trains are traveling towards each other from two cities that are 720 km apart. The first train is traveling at a speed of 38 km/h, and the second train is traveling at a speed of 52 km/h. We need to determine how many hours it will take for the trains to meet.

Solution

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

Let's calculate the time it will take for the trains to meet.

The total distance between the two cities is 720 km. Since the trains are traveling towards each other, the effective distance they need to cover to meet is the sum of their distances from the starting point.

Let's assume that the first train travels for 't' hours before meeting the second train. Therefore, the distance covered by the first train is 38t km. Similarly, the distance covered by the second train is 52t km.

The sum of the distances covered by both trains should be equal to the total distance between the two cities:

38t + 52t = 720

Simplifying the equation:

90t = 720

Dividing both sides of the equation by 90:

t = 720 / 90

t = 8

Therefore, it will take 8 hours for the trains to meet.

Answer

The trains will meet after 8 hours.

Explanation

The first train is traveling at a speed of 38 km/h, and the second train is traveling at a speed of 52 km/h. Since they are traveling towards each other, the effective speed at which they are approaching each other is the sum of their speeds.

The effective speed is 38 km/h + 52 km/h = 90 km/h.

To calculate the time it will take for the trains to meet, we divide the total distance between the two cities (720 km) by the effective speed:

Time = Distance / Speed = 720 km / 90 km/h = 8 hours.

Therefore, the trains will meet after 8 hours.