Question

Снаряд массой 20кг летит со скоростью 500м/с и попадает в вагон с песком массой 800кг, который двигался со скоростью 1м/с. С какой скоростью вагон продолжит движение?

Answer 1

Если снаряд догоняет вагон m1*V1+m2*V2=(m1+m2)*V
V=m1*V1+m2*V2/(m1+m2)=20*500+800*1/(20+800)=13,2 м/с
В случае встречного движения пишем m1*V1-m2*V2

Answer 2

Calculation of the Final Velocity of the Wagon

To calculate the final velocity of the wagon after the projectile hits it, 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 given by the product of its mass and velocity. Therefore, we can calculate the momentum of the projectile and the wagon before the collision and set it equal to the momentum of the wagon after the collision.

Let's denote the mass of the projectile as m1 (20 kg) and its velocity as v1 (500 m/s). The mass of the wagon is m2 (800 kg), and its velocity is v2 (1 m/s).

The total momentum before the collision is given by:

Total momentum before collision = momentum of the projectile + momentum of the wagon

m1 * v1 + m2 * v2

Substituting the given values:

20 kg * 500 m/s + 800 kg * 1 m/s

Simplifying the equation:

10,000 kg·m/s + 800 kg·m/s

10,800 kg·m/s

The total momentum after the collision is also equal to the momentum of the wagon, which we'll denote as v_f.

Therefore, we can set up the equation:

Total momentum after collision = m2 * v_f

Substituting the values:

10,800 kg·m/s = 800 kg * v_f

Solving for v_f:

v_f = 10,800 kg·m/s / 800 kg

v_f = 13.5 m/s

Therefore, the wagon will continue moving with a velocity of 13.5 m/s after the projectile hits it.