Question

Снаряд массой 30 кг летит со скоростью 400м/с разорвался на 2 осколка осколок массой 10 кг приобрел скорость 600 мс. сравните суммарную К энергию омколоков с К энергией снаряда до разрыва.

Answer 1

До разрыва К Э  30*(400)^2/2=2 400 000 Дж
после разрыва суммарная КЭ обоих осколков не изменилась (з-н сохр энергии)
1 осколок КЭ 10*(600)^2/2= 1 800 000 Дж
2 осколок КЭ  2 400 000 - 1 800 000= 600 000 Дж
масса 2 осколка 30-10= 20 кг (если их всего 2)
скорость 2 осколка V^2=600 000/20=3*10^4  V=1,73*10^2=173 м/с

Answer 2

Calculation of Kinetic Energy:

To compare the total kinetic energy of the two fragments with the kinetic energy of the projectile before the explosion, we need to calculate the kinetic energy of each fragment.

The formula for kinetic energy is:

Kinetic Energy (KE) = (1/2) * mass * velocity^2

Let's calculate the kinetic energy of the two fragments and compare it with the kinetic energy of the projectile before the explosion.

1. Kinetic Energy of the Projectile (before explosion): - Mass of the projectile (m1) = 30 kg - Velocity of the projectile (v1) = 400 m/s

Using the formula, the kinetic energy of the projectile is:

KE1 = (1/2) * m1 * v1^2

2. Kinetic Energy of Fragment 1: - Mass of Fragment 1 (m2) = 10 kg - Velocity of Fragment 1 (v2) = 600 m/s

Using the formula, the kinetic energy of Fragment 1 is:

KE2 = (1/2) * m2 * v2^2

3. Kinetic Energy of Fragment 2: Since there are only two fragments, we can calculate the kinetic energy of Fragment 2 by subtracting the kinetic energy of Fragment 1 from the total kinetic energy of the projectile before the explosion.

KE3 = KE1 - KE2

This is because the total kinetic energy before the explosion is equal to the sum of the kinetic energies of the two fragments after the explosion.

Calculation Results:

Let's calculate the values using the given information:

1. Kinetic Energy of the Projectile (before explosion): - Mass of the projectile (m1) = 30 kg - Velocity of the projectile (v1) = 400 m/s

KE1 = (1/2) * 30 kg * (400 m/s)^2

2. Kinetic Energy of Fragment 1: - Mass of Fragment 1 (m2) = 10 kg - Velocity of Fragment 1 (v2) = 600 m/s

KE2 = (1/2) * 10 kg * (600 m/s)^2

3. Kinetic Energy of Fragment 2: KE3 = KE1 - KE2

Now, let's calculate the values:

1. Kinetic Energy of the Projectile (before explosion): KE1 = (1/2) * 30 kg * (400 m/s)^2

The kinetic energy of the projectile before the explosion is 240,000 Joules.

2. Kinetic Energy of Fragment 1: KE2 = (1/2) * 10 kg * (600 m/s)^2

The kinetic energy of Fragment 1 is 180,000 Joules.

3. Kinetic Energy of Fragment 2: KE3 = KE1 - KE2

Substituting the values, we get:

KE3 = 240,000 Joules - 180,000 Joules

The kinetic energy of Fragment 2 is 60,000 Joules.

Comparison of Kinetic Energies:

To compare the sum of the kinetic energies of the two fragments with the kinetic energy of the projectile before the explosion, we need to add the kinetic energies of the two fragments.

The sum of the kinetic energies of the two fragments is:

Sum of Kinetic Energies = KE2 + KE3

Substituting the values, we get:

Sum of Kinetic Energies = 180,000 Joules + 60,000 Joules

The sum of the kinetic energies of the two fragments is 240,000 Joules.

Therefore, the sum of the kinetic energies of the two fragments is equal to the kinetic energy of the projectile before the explosion.