Question

Поезд длиной 180 метров проезжает мимо столба за 9 секунд. Сколько времени нужно поезду чтобы проехать мост длиной 360 метров? С какой скоростью движется поезд? Скорость подсчитать в м/с. и в км/ч.

Answer 1

Ответ:

27 секунд

Пошаговое объяснение:

V поезда = 180/9 = 20м/с или 72км/ч

Чтобы проехать мост нужно проехать 360 (длина моста) + 180 (длина поезда) = 540м (S = 540м).

T = S/V = 540м/20м/с = 27c

P.S. мы прибавили 180м к расстаянию, т.к. поезду нужно ПОЛНОСТЬЮ выйти с моста. То есть когда он доедет до конца моста, можно сказать, что настанет случай со столбом. Значит останиться ещё 180м.

Answer 2

Problem Analysis

We are given that a train with a length of 180 meters passes a pole in 9 seconds. We need to determine how much time it will take for the train to cross a bridge with a length of 360 meters. Additionally, we need to calculate the speed of the train in meters per second (m/s) and kilometers per hour (km/h).

Calculating the Time to Cross the Bridge

To calculate the time it takes for the train to cross the bridge, we can use the concept of relative speed. The train's length is 180 meters, and it takes 9 seconds to pass a stationary point. Therefore, the train's speed is given by:

Speed = Distance / Time

The distance covered by the train to cross the bridge is the sum of the train's length and the bridge's length, which is 180 meters + 360 meters = 540 meters.

Let's calculate the time it takes for the train to cross the bridge:

Time = Distance / Speed

Calculation

The train's speed is given by the formula:

Speed = Distance / Time

Substituting the values, we have:

Speed = 540 meters / 9 seconds

Simplifying, we find:

Speed = 60 meters/second

Calculating the Speed in Kilometers per Hour (km/h)

To calculate the speed in kilometers per hour, we need to convert the speed from meters per second to kilometers per hour. We know that 1 kilometer is equal to 1000 meters, and 1 hour is equal to 3600 seconds.

Let's calculate the speed in kilometers per hour:

Speed (km/h) = Speed (m/s) * (3600 seconds / 1000 meters)

Calculation

Substituting the value of the speed in meters per second, we have:

Speed (km/h) = 60 meters/second * (3600 seconds / 1000 meters)

Simplifying, we find:

Speed (km/h) = 216 kilometers/hour

Summary of Results

- The time it takes for the train to cross the bridge is 9 seconds. - The speed of the train is 60 meters/second. - The speed of the train is 216 kilometers/hour.

Please let me know if I can help you with anything else.