Question

Решите пожалуйста задачу с дано!!!!!пассажир поезда, идущего со V 40км/ч, видит в течении 3 с встречный поезд длинной 75 м. С какой V движ. встречн. поезд?

Answer 1

Дано V1=40 км/ч=40*1000/3600=11,11111 м/с

L= (V1+V2)*t

V2=L/t-V1=25-11,1=13,89 м/с=50 км/ч

Answer 2

Problem Statement

Пассажир поезда, идущего со скоростью V = 40 км/ч, видит в течение 3 секунды встречный поезд длиной 75 метров. С какой скоростью движется встречный поезд?

Solution

To solve this problem, we can use the formula for relative velocity. The relative velocity between two objects moving in opposite directions is the sum of their individual velocities.

Let's denote the velocity of the passenger's train as V1 and the velocity of the oncoming train as V2. The relative velocity between the two trains is the difference between their velocities:

Relative velocity = V1 - V2

We know that the passenger's train is moving at V1 = 40 km/h. We need to find the velocity of the oncoming train, V2.

We also know that the passenger sees the oncoming train for 3 seconds. During this time, the oncoming train covers a distance equal to its length, which is 75 meters.

Using the formula for distance, speed, and time:

Distance = Speed × Time

We can rearrange the formula to solve for the velocity of the oncoming train:

V2 = (V1 × T1) / T2

Where: - V1 is the velocity of the passenger's train (40 km/h) - T1 is the time the passenger sees the oncoming train (3 seconds) - T2 is the time it takes for the oncoming train to cover its length (75 meters)

Let's calculate the velocity of the oncoming train using these values:

V2 = (40 km/h × 3 s) / 75 m

Converting the units to a consistent system (m/s):

V2 = (40 km/h × 1000 m/1 km × 1 h/3600 s × 3 s) / 75 m

Simplifying the expression:

V2 = 40 × 1000 × 1 / 3600 × 3 / 75 m/s

Evaluating the expression:

V2 = 40000 / 10800 m/s

Simplifying the fraction:

V2 ≈ 3.7037 m/s

Therefore, the velocity of the oncoming train is approximately 3.7037 m/s.