Question

б) Решите задачу: Вагон массой 30000 кг, движущийся по горизонтальному пути со скоростью 2,5 м/с, автоматически на ходу сцепляется вагоном массой 20000 кг, который движгался со скоростью 1,2 м/с.. С какой скоростью движутся вагоны после сцепки?​

Answer 1

Ответ:

U = 1.98 м/с

Объяснение:

Простейшее применение закона сохранения импульса: считаем сколько импульса было до взаимодействия, затем после; приравниваем их и находим нужную величину. В данном случае общую скорость вагонов (U).

Answer 2

Ответ: 1,98м/с

Объяснение:

Дано:

m1=30000кг

V1=2,5м/с

m2=20000кг

V2=1,2м/с

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V-?

m1V1+m2V2=V(m1+m2)

V=(m1V1+m2V2)/(m1+m2)=(30000*2,5+20000*1,2)/(30000+20000)=1,98м/с

Answer 3

Problem Analysis

We are given two wagons with their respective masses and velocities. The first wagon has a mass of 30,000 kg and is moving with a velocity of 2.5 m/s. The second wagon has a mass of 20,000 kg and is moving with a velocity of 1.2 m/s. We need to find the velocity of the wagons after they are coupled together.

Solution

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

The momentum of an object is given by the product of its mass and velocity. Mathematically, momentum (p) is defined as:

p = m * v

where p is the momentum, m is the mass, and v is the velocity.

Let's denote the velocity of the coupled wagons as V. The total momentum before the coupling is the sum of the individual momenta of the two wagons:

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

Total momentum before = (30,000 kg * 2.5 m/s) + (20,000 kg * 1.2 m/s)

Now, let's calculate the total momentum before the coupling:

Total momentum before = (75,000 kg*m/s) + (24,000 kg*m/s) = 99,000 kg*m/s

According to the principle of conservation of momentum, the total momentum after the coupling is also equal to 99,000 kg*m/s.

The total momentum after the coupling is the product of the total mass of the coupled wagons and their common velocity:

Total momentum after = (total mass of coupled wagons) * V

The total mass of the coupled wagons is the sum of the masses of the individual wagons:

Total mass of coupled wagons = mass of first wagon + mass of second wagon

Total mass of coupled wagons = 30,000 kg + 20,000 kg = 50,000 kg

Now, let's calculate the velocity of the wagons after the coupling:

Total momentum after = (total mass of coupled wagons) * V

99,000 kg*m/s = (50,000 kg) * V

Solving for V:

V = 99,000 kg*m/s / 50,000 kg

V ≈ 1.98 m/s

Therefore, the wagons move with a velocity of approximately 1.98 m/s after the coupling.

Answer

The wagons move with a velocity of approximately 1.98 m/s after the coupling.