Question

Мост длиной 475 м поезд проходит за 45с, а мимо дежурного по станции-за 20 с. Найдите скорость поезда и длину поезда.

Answer 1

Calculation of Train Speed and Length

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

Speed = Distance / Time

Let's denote the length of the train as 'L' and the speed of the train as 'v'. We are given the following information:

- The train takes 45 seconds to pass a bridge with a length of 475 meters. - The train takes 20 seconds to pass a stationmaster standing by the station.

We can set up the following equations:

Equation 1: L + 475 = v * 45 (The total distance covered by the train when passing the bridge) Equation 2: L = v * 20 (The distance covered by the train when passing the stationmaster)

To solve these equations, we can use a substitution method. We'll solve Equation 2 for 'L' and substitute it into Equation 1:

v * 20 + 475 = v * 45

Now, let's solve this equation to find the value of 'v':

20v + 475 = 45v

45v - 20v = 475

25v = 475

v = 475 / 25

v = 19 m/s

Now that we have the value of 'v', we can substitute it back into Equation 2 to find the length of the train 'L':

L = 19 * 20

L = 380 meters

Therefore, the speed of the train is 19 m/s and the length of the train is 380 meters.

Please note that the above calculations are based on the information provided.