Question

Пожааалуйста!!! Это задача из КОНТРОЛЬНОЙ РАБОТЫ!! ОЧЕНЬ ПРОШУ!!! Вагон массой 5т движется со скоростью 2 м/с, навстречу ему движется 2 вагон со скоростью 1 м/с, и массой 8т. Определить скорость и направление их движения.

Answer 1

Через закон сохранения импульса; m1V1+m2V2=m1V01+m2V02 (в векторном виде), если Fтр->0
(OX):m1V1-(m2V2)=Vобщ(m1+m2)
Vобщ=(m1V1-m2V2)\m1+m2≈0,15м\с
Т.к. знак положительный, то скорость будет направлена в сторону первого вагона

Answer 2

Problem Analysis

We are given two wagons moving towards each other. The first wagon has a mass of 5 tons and a velocity of 2 m/s, while the second wagon has a mass of 8 tons and a velocity of 1 m/s. We need to determine the final velocity and direction of their movement.

Solution

To solve this problem, we can use the principle of conservation of momentum. According to this principle, the total momentum before the collision is equal to the total momentum after the collision.

The momentum of an object is calculated by multiplying its mass by its velocity. Therefore, the momentum of the first wagon before the collision is given by:

Momentum of first wagon before collision = mass of first wagon * velocity of first wagon

Similarly, the momentum of the second wagon before the collision is given by:

Momentum of second wagon before collision = mass of second wagon * velocity of second wagon

Since the wagons are moving towards each other, their velocities have opposite directions. We can assign a positive direction to the first wagon and a negative direction to the second wagon. This allows us to write the equation for the total momentum before the collision as:

Total momentum before collision = (mass of first wagon * velocity of first wagon) - (mass of second wagon * velocity of second wagon)

After the collision, the wagons will stick together and move with a common final velocity. Let's call this final velocity V. The total momentum after the collision is then given by:

Total momentum after collision = (mass of first wagon + mass of second wagon) * final velocity

Since the total momentum before the collision is equal to the total momentum after the collision, we can set up the following equation:

(mass of first wagon * velocity of first wagon) - (mass of second wagon * velocity of second wagon) = (mass of first wagon + mass of second wagon) * final velocity

Now we can substitute the given values into the equation and solve for the final velocity.

Calculation

Given: - Mass of first wagon = 5 tons - Velocity of first wagon = 2 m/s - Mass of second wagon = 8 tons - Velocity of second wagon = 1 m/s

Substituting these values into the equation, we get:

(5 * 2) - (8 * 1) = (5 + 8) * final velocity

Simplifying the equation, we have:

10 - 8 = 13 * final velocity

2 = 13 * final velocity

Dividing both sides of the equation by 13, we find:

final velocity = 2/13 m/s

Answer

The final velocity of the wagons after the collision is 2/13 m/s. The direction of their movement is not specified in the problem, so we cannot determine it based on the given information.