Question

4. Грузовой поезд длиной 500 м со скоростью 90 км/ч и пассажирский поезд длиной 150 м со скоростью 144 км/ч движутся в одном направлении по двум параллельным железнодорожным путям. Через какое время первый поезд догонит второй поезд?

Answer 1

чо надо писать в ответе если я у вас спрашиваю ответ

Answer 2

Problem Analysis

We are given the lengths and speeds of a cargo train and a passenger train moving in the same direction on parallel railway tracks. We need to determine the time it takes for the first train to catch up to the second train.

Solution

To solve this problem, we can use the concept of relative speed. The relative speed of the first train with respect to the second train is the difference between their speeds. We can calculate the relative speed and then use it to find the time it takes for the first train to catch up to the second train.

Let's calculate the relative speed and the time it takes for the first train to catch up to the second train.

Calculation

Given: - Length of the cargo train = 500 m - Speed of the cargo train = 90 km/h - Length of the passenger train = 150 m - Speed of the passenger train = 144 km/h

To calculate the relative speed, we subtract the speed of the second train from the speed of the first train: Relative speed = Speed of the first train - Speed of the second train

Let's convert the speeds from km/h to m/s for consistency: Speed of the first train = 90 km/h = (90 * 1000) m/3600 s = 25 m/s Speed of the second train = 144 km/h = (144 * 1000) m/3600 s = 40 m/s

Relative speed = 25 m/s - 40 m/s = -15 m/s (negative because the first train is slower than the second train)

Now, we can calculate the time it takes for the first train to catch up to the second train using the formula: Time = Distance / Relative speed

Let's substitute the values: Time = (Length of the second train - Length of the first train) / Relative speed Time = (150 m - 500 m) / -15 m/s Time = -350 m / -15 m/s Time = 23.33 s

Answer

The first train will catch up to the second train in approximately 23.33 seconds.

Please note that the negative sign in the relative speed indicates that the first train is slower than the second train.