Question

Из 2 городов навстречу друг другу едут 2 поезда сежду ними 800км. Встречаются они через 5 часов. Найти скорость 2го поезда, и расстояние через 3 часа

Answer 1

800:5=160
160×3=480
Ответ 480км/ч

Answer 2

Problem Analysis

We are given that two trains are traveling towards each other from two different cities. The distance between the cities is 800 km. The trains meet each other after 5 hours. We need to find the speed of the second train and the distance between the trains after 3 hours.

Solution

Let's assume the speed of the first train is v1 and the speed of the second train is v2.

To find the speed of the second train, we can use the formula:

Distance = Speed × Time

Since the two trains are traveling towards each other, the total distance covered by both trains is equal to the distance between the cities, which is 800 km. Therefore, we can write the equation:

800 = (v1 + v2) × 5 To find the distance between the trains after 3 hours, we can use the formula:

Distance = Speed × Time

For the first train, the distance covered in 3 hours is 3 × v1. For the second train, the distance covered in 3 hours is 3 × v2. Therefore, the distance between the trains after 3 hours is:

Distance = (3 × v1) + (3 × v2)

Now, we can solve these equations to find the speed of the second train and the distance between the trains after 3 hours.

Calculation

Let's solve the equations:

From equation we have:

800 = (v1 + v2) × 5

Simplifying the equation, we get:

160 = v1 + v2 To find the distance between the trains after 3 hours, we have:

Distance = (3 × v1) + (3 × v2)

Substituting the value of v1 + v2 from equation we get:

Distance = (3 × v1) + (3 × (160 - v1))

Simplifying the equation, we get:

Distance = 3v1 + 480 - 3v1

Simplifying further, we get:

Distance = 480

Therefore, the distance between the trains after 3 hours is 480 km.

Now, let's solve equation to find the speed of the second train:

160 = v1 + v2

Rearranging the equation, we get:

v2 = 160 - v1

Therefore, the speed of the second train is 160 - v1.

Answer

The speed of the second train is 160 - v1 and the distance between the trains after 3 hours is 480 km.

Please note that the value of v1 needs to be provided in order to calculate the speed of the second train.