Question

Два поезда движуться навстречу друг другу со скоростью 72км/ч и 54км/ч поезде замечает что второй поезд проходит мимо него в течени 14 секунд какова длина второго поезда

Answer 1

Найдем скорость второго поезда относительно первого
V=V1+V2=54+72=126 км/ч
Переведем км/ч в м/с
V=126 *1000/3600=35м/с
Найдем длину поезда
L=35*14=490 метров

Answer 2

Problem Analysis

We are given two trains moving towards each other at speeds of 72 km/h and 54 km/h. The first train notices that the second train passes by it in 14 seconds. We need to find the length of the second train.

Solution

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

Length = Speed × Time

Let's calculate the length of the second train using this formula.

Calculation

Given: - Speed of the first train = 72 km/h - Speed of the second train = 54 km/h - Time taken for the second train to pass the first train = 14 seconds

To find the length of the second train, we need to convert the speeds from km/h to m/s and the time from seconds to hours.

Converting the speeds: - Speed of the first train = 72 km/h = (72 × 1000) m/3600 s = 20 m/s - Speed of the second train = 54 km/h = (54 × 1000) m/3600 s = 15 m/s

Converting the time: - Time taken for the second train to pass the first train = 14 seconds = 14/3600 hours

Now, we can calculate the length of the second train using the formula:

Length = Speed × Time

Length = (15 m/s) × (14/3600 hours)

Simplifying the calculation: Length = (15 × 14) / (3600) meters

Calculating the length: Length = 0.05833333333 meters

Answer

The length of the second train is approximately 0.058 meters.

Explanation

The length of the second train is calculated by multiplying the speed of the second train by the time it takes to pass the first train. The speed of the second train is 15 m/s, and the time taken is 14 seconds. Therefore, the length of the second train is approximately 0.058 meters.