Question

По двум параллельным железнодорожным путям друг навстречу другу следуют скорый и пассажирский поезда, скорости которых соответственно 60 км/ч и 40 км/ч. Длина пассажирского поезда равна 450 метрам. Найдите длину скорого поезда, если время, за которое он прошёл мимо пассажирского поезда, равно 36 секундам.

Answer 1

скорость движения поездов навстречу друг другу = 100 км/ч = 100/60 км/мин = 100000/60 м/мин = 100000/3600 м/с = 1000/36 м/с

за 36 секунд они проедут друг относительно друга = 36 * 1000/36 = 1000 метров

если длина пассажирского состава 450м то скорого = 1000-450 = 550м

Answer 2

Problem Analysis

We are given two parallel railway tracks on which a fast train and a passenger train are traveling towards each other. The speeds of the trains are given, as well as the length of the passenger train. We need to find the length of the fast train based on the time it takes to pass the passenger train.

Solution

Let's denote the length of the fast train as x. We can use the formula:

Distance = Speed × Time

The distance covered by the fast train while passing the passenger train is equal to the sum of the lengths of the passenger train and the fast train. The time taken by the fast train to pass the passenger train is given as 36 seconds.

Using the formula, we can set up the following equation:

Distance = (Speed of fast train) × (Time taken to pass the passenger train)

x + 450 = 60 × 36

Now we can solve this equation to find the value of x.

Calculation

Let's calculate the length of the fast train.

x + 450 = 60 × 36

x + 450 = 2160

x = 2160 - 450

x = 1710

Answer

The length of the fast train is 1710 meters.

Explanation

The fast train takes 36 seconds to pass the passenger train. The speed of the fast train is 60 km/h, which is equivalent to 60,000 meters per hour or 16.67 meters per second. Therefore, in 36 seconds, the fast train covers a distance of 60 × 36 = 2160 meters. Since the length of the passenger train is 450 meters, the remaining distance is covered by the fast train, which is equal to the length of the fast train. Hence, the length of the fast train is 2160 - 450 = 1710 meters.