Question

Мост длиной 475 км поезд проходит за 45 секунд с такой же скоростью он проходит мимо дежурного по станции за 20 секунд Найдите скорость поезда Найдите длину поезда

Answer 1

475 м:45 с=10 25/45 м/с=10 5/9 м/с (скорость)
(10 5/9:1000*3600=38 (км/ч))
10 5/9 м/с*20 с=95/9 м/с*20 с=211 1/9 м (длина)
Ответ: скорость поезда 10 5/9 м/с (38 км/ч)
             длина поезда 211 1/9 м

Answer 2

Calculation of Train Speed and Length

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

Speed = Distance / Time

Given that the train passes a bridge of length 475 km in 45 seconds and passes a station guard in 20 seconds, we can calculate the speed of the train.

Let's denote the speed of the train as v and the length of the train as L.

1. Calculation of Train Speed: - Distance = Length of the bridge = 475 km - Time = 45 seconds - Using the formula, Speed = Distance / Time, we can calculate the speed of the train passing the bridge. - Speed = 475 km / 45 seconds

2. Calculation of Train Length: - Distance = Length of the train = L (unknown) - Time = 20 seconds - Using the formula, Speed = Distance / Time, we can calculate the length of the train passing the station guard. - Speed = L / 20 seconds

To find the speed of the train, we need to equate the two expressions for speed:

475 km / 45 seconds = L / 20 seconds

Now, let's solve this equation to find the speed of the train and the length of the train.

Solution:

To solve the equation, we can cross-multiply:

475 km * 20 seconds = 45 seconds * L

Simplifying the equation:

L = (475 km * 20 seconds) / 45 seconds

Now, let's calculate the length of the train using this equation.

L = (475 km * 20 seconds) / 45 seconds

L = (475 km * 20) / 45

L = 9500 km / 45

L = 211.11 km

Therefore, the length of the train is approximately 211.11 km.

Now, let's calculate the speed of the train using the equation:

Speed = 475 km / 45 seconds

Speed = 10.56 km/s

Therefore, the speed of the train is approximately 10.56 km/s.

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