Question

Два поезда идут навстречу один другому со скоростью 45км/ч. Длина каждого поезда 250м . Сколько секунд пройдет с момента встречи машинистов до момента встречи проводников, стоящих у последних дверей последних вагонов?

Answer 1

1) 45+45=90 (км/ч) - скорость сближения
2) 250+250=500 (м) - расстояние между последними дверями последних вагонов
90км/ч скорость поезда 90км за 1 мин =90000м за 360сек=25м/сек 90000/360=25
3) 500:25=20 (сек)
Ответ: 20 секунд пройдет с момента встречи машинистов до момента встречи проводников, стоящих у последних дверей последних вагонов.

Answer 2

Calculation of the Time Taken for the Conductors to Meet

To calculate the time taken for the conductors to meet, we need to consider the relative speed of the two trains and the distance between them.

Given: - Speed of each train: 45 km/h - Length of each train: 250 m

To find the time taken for the conductors to meet, we need to calculate the time it takes for the two trains to cover the distance between them.

Calculation Steps:

1. Convert the speed of each train from km/h to m/s: - Speed of each train = 45 km/h = (45 * 1000) m/3600 s = 12.5 m/s

2. Calculate the relative speed of the two trains: - Relative speed = Speed of train A + Speed of train B - Relative speed = 12.5 m/s + 12.5 m/s = 25 m/s

3. Calculate the distance between the two trains: - Distance = Length of train A + Length of train B - Distance = 250 m + 250 m = 500 m

4. Calculate the time taken for the conductors to meet: - Time = Distance / Relative speed - Time = 500 m / 25 m/s = 20 s

Therefore, it will take 20 seconds for the conductors to meet from the moment the train drivers meet until the conductors meet at the last doors of the last carriages.