Question

Электровоз массой 180 т, движущийся со скоростью 1 м/с, сталкивается с неподвижным вагоном массой 60 т, после чего они движутся вместе. Определите скорость их совместного движения.

Answer 1

Вот

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Answer 2

Calculation of the Combined Velocity

To determine the combined velocity of the electric locomotive and the stationary wagon after the collision, 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. In this case, we have an electric locomotive with a mass of 180 tons and a velocity of 1 m/s, and a stationary wagon with a mass of 60 tons.

Before the collision, the electric locomotive has a momentum of 180 tons * 1 m/s = 180 ton·m/s. The stationary wagon has zero velocity, so its momentum is zero.

After the collision, the two objects move together with a combined velocity. Let's denote this velocity as V. The total momentum after the collision is the sum of the momenta of the electric locomotive and the wagon.

The momentum of the electric locomotive after the collision is its mass (180 tons) multiplied by the combined velocity (V). The momentum of the wagon after the collision is its mass (60 tons) multiplied by the combined velocity (V).

According to the principle of conservation of momentum, the total momentum before the collision is equal to the total momentum after the collision. Therefore, we can set up the following equation:

180 ton·m/s + 0 = 180 ton·m/s + 60 ton * V + 60 ton * V

Simplifying the equation, we get:

0 = 120 ton * V

To solve for V, we divide both sides of the equation by 120 tons:

V = 0 m/s

Therefore, the combined velocity of the electric locomotive and the stationary wagon after the collision is 0 m/s. They will remain stationary together.