Question

Два поезда идут навстречу другу со скоростью 45км/ч . длина каждого поезда 250м. сколько секунд пройдёт с момента встречи машинистов до момента встречи проводников , стоящих у последних дверей последних вагонов?

Answer 1

Ну напиши скорость время и расстояние
а потом все найдешь

Answer 2

Calculating the Time for the Meeting of the Conductors

To calculate the time it takes for the conductors to meet, we can use the following steps:

1. Calculate the Relative Speed of the Trains: Since the trains are moving towards each other, their relative speed is the sum of their individual speeds. Given that each train is moving at a speed of 45 km/h, the relative speed is 45 km/h + 45 km/h = 90 km/h.

2. Convert the Relative Speed to m/s: To work with the length of the trains in meters, we need to convert the relative speed from km/h to m/s. The conversion factor is 1 m/s = 3.6 km/h.

3. Calculate the Time for the Meeting: Once we have the relative speed in m/s, we can use the formula: time = distance / speed.

Calculation Steps

1. Calculate Relative Speed: - The relative speed of the trains is 45 km/h + 45 km/h = 90 km/h.

2. Convert Relative Speed to m/s: - 90 km/h * (1 m/s / 3.6 km/h) = 25 m/s.

3. Calculate Time for the Meeting: - The length of each train is 250 meters, so the total distance covered by both trains is 250m + 250m = 500m. - Time = distance / speed = 500m / 25 m/s = 20 seconds.

Therefore, the time it takes for the conductors to meet is 20 seconds.