Question

Помогите пожалуйста, у меня мало времени Железнодорожная платформа движется со скоростью 5 км/ч. Из орудия, закреплённого на платформе, производится выстрел в направлении против движения платформы. Масса снаряда — 24 кг, его скорость — 743 м/с. Масса платформы с орудием — 21 т. Определи скорость платформы после выстрела.​

Answer 1

Ответ:

8 км/ч

Объяснение:

v1=1.39 м/с (5 км/ч)    m=24 кг    v2=743 м/с    M=21*10³ кг    v=?

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M>>m

M*v1= -m*v2 + M*v

v=v1 + *v2/M=1.39 + 24*743/(21*10³)≈2.24 м/с (8 км/ч)

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Answer 2

Calculation of the Platform's Speed After Firing

To calculate the speed of the platform after the shot is fired, we can use the principle of conservation of momentum. According to this principle, the total momentum before the shot is equal to the total momentum after the shot.

The momentum of an object is calculated by multiplying its mass by its velocity. In this case, we have two objects: the platform with the gun and the projectile.

Let's denote the initial velocity of the platform as v_platform_initial, the final velocity of the platform as v_platform_final, the mass of the platform with the gun as m_platform, the velocity of the projectile as v_projectile, and the mass of the projectile as m_projectile.

The total momentum before the shot is given by the sum of the momentum of the platform and the momentum of the projectile:

Total momentum before = (m_platform * v_platform_initial) + (m_projectile * v_projectile)

After the shot, the platform and the projectile will have new velocities. Let's denote the final velocity of the projectile as v_projectile_final.

The total momentum after the shot is given by the sum of the momentum of the platform and the momentum of the projectile:

Total momentum after = (m_platform * v_platform_final) + (m_projectile * v_projectile_final)

According to the principle of conservation of momentum, the total momentum before the shot is equal to the total momentum after the shot:

(m_platform * v_platform_initial) + (m_projectile * v_projectile) = (m_platform * v_platform_final) + (m_projectile * v_projectile_final)

We can rearrange this equation to solve for the final velocity of the platform:

v_platform_final = (m_platform * v_platform_initial) + (m_projectile * v_projectile) - (m_projectile * v_projectile_final) / m_platform

Now let's substitute the given values into the equation and calculate the final velocity of the platform.

Given: - Initial velocity of the platform (v_platform_initial) = 5 km/h = 5000 m/3600 s ≈ 1.39 m/s - Mass of the platform with the gun (m_platform) = 21 tons = 21,000 kg - Velocity of the projectile (v_projectile) = 743 m/s - Mass of the projectile (m_projectile) = 24 kg

Substituting these values into the equation, we get:

v_platform_final = (21,000 kg * 1.39 m/s) + (24 kg * 743 m/s) - (24 kg * v_projectile_final) / 21,000 kg

To determine the final velocity of the platform, we need to know the final velocity of the projectile (v_projectile_final). Unfortunately, the given information does not provide this value. Therefore, we cannot calculate the final velocity of the platform without knowing the final velocity of the projectile.

Please provide the final velocity of the projectile so that we can calculate the final velocity of the platform.