Question

Пассажир заметил, что поезд, в котором он едет, прошел мимо стоящего поезда длиной 100 м за 5 с, а встречный поезд длиной 60м прошел мимо окна за 2с. Найдите скорость поезда, в котором ехал пассажир и скорость встречного поезда.

Answer 1

100÷5=20м/с-скорость поезд
60÷2=30м/с-скорость встр.поезда

Answer 2

Problem Analysis

A passenger on a train noticed that the train passed a stationary train of length 100m in 5 seconds, and a train coming from the opposite direction, with a length of 60m, passed the window in 2 seconds. We need to find the speed of the passenger's train and the speed of the oncoming train.

Solution

Let's assume the speed of the passenger's train is v m/s and the speed of the oncoming train is u m/s.

To find the speed of the passenger's train, we can use the formula: Speed = Distance / Time

The distance covered by the passenger's train in 5 seconds is the sum of the lengths of the stationary train and the passenger's train. Therefore, the distance is 100m + length of the passenger's train.

The distance covered by the oncoming train in 2 seconds is the sum of the lengths of the oncoming train and the passenger's train. Therefore, the distance is 60m + length of the passenger's train.

We can set up the following equations:

Equation 1: (100 + length of the passenger's train) / 5 = v

Equation 2: (60 + length of the passenger's train) / 2 = u

We have two equations and two unknowns, so we can solve for the length of the passenger's train, the speed of the passenger's train, and the speed of the oncoming train.

Let's solve the equations:

From Equation 1, we can express the length of the passenger's train in terms of v: length of the passenger's train = 5v - 100

Substituting this into Equation 2, we get: (60 + 5v - 100) / 2 = u

Simplifying the equation: (5v - 40) / 2 = u

Now, we have two equations with two unknowns. We can solve them simultaneously to find the values of v and u.

Calculation

Let's solve the equations:

Equation 1: (100 + length of the passenger's train) / 5 = v

Substituting the expression for the length of the passenger's train: (100 + (5v - 100)) / 5 = v

Simplifying the equation: (5v) / 5 = v

Therefore, the length of the passenger's train is equal to v.

Equation 2: (60 + length of the passenger's train) / 2 = u

Substituting the expression for the length of the passenger's train: (60 + (5v - 100)) / 2 = u

Simplifying the equation: (5v - 40) / 2 = u

Now, we have two equations with two unknowns. We can solve them simultaneously to find the values of v and u.

Solution

To find the values of v and u, we can solve the equations simultaneously:

Equation 1: v = (5v) / 5

Simplifying the equation: v = v

This equation is true for any value of v.

Equation 2: (5v - 40) / 2 = u

Simplifying the equation: 5v - 40 = 2u

Let's rearrange the equation to solve for u: 2u = 5v - 40 u = (5v - 40) / 2

Therefore, the speed of the passenger's train is v m/s, and the speed of the oncoming train is (5v - 40) / 2 m/s.

Answer

The speed of the passenger's train is v m/s, and the speed of the oncoming train is (5v - 40) / 2 m/s.

Please note that we were unable to find the exact values of v and u without additional information.