Question

ДАЮ 50 балів!ФІЗИКА ДУЖЕ ТРЕБА Куля, що рухалася зі швидкістю v0, зазнала лобового пружного зіткнення з нерухомим кубом. Установіть відповідність «напрямок і модуль кінцевої швидкості руху v кулі – співвідношення мас кулі та куба». А)Куля відскочила назад, v практично дорівнює v0 Б)Куля зупинилася, v дорівнює 0 В)Куля відскочила назад, v дорівнює 0,5*v0 Г)Напрямок руху кулі не змінився, v дорівнює 0,5*v0 1)маса кулі в кілька разів менша за масу куба 2)маса кулі дорівнює масі куба 3)маса кулі в багато разів більша за масу куба 4)маса кулі в кілька разів більша за масу куба 5)маса кулі в багато разів менша за масу куба

Answer 1

Ответ:Куля відскочила назад, v дорівнює 0,5*v0 → маса кулі в кілька разів менша за масу куба, Куля відскочила назад, v практично дорівнює v0 → маса кулі в багато разів менша за масу куба, Куля зупинилася, v дорівнює 0 → маса кулі дорівнює масі куба, Напрямок руху кулі не змінився, v дорівнює 0,5*v0 → маса кулі в кілька разів більша за масу куба

Объяснение:

Answer 2

Problem Analysis

The problem states that a ball moving with an initial velocity v0 undergoes a head-on elastic collision with a stationary cube. We need to determine the relationship between the final velocity v of the ball and the masses of the ball and the cube.

Solution

To solve this problem, we can apply the principle of conservation of linear momentum and the principle of conservation of kinetic energy.

According to the principle of conservation of linear momentum, the total momentum before the collision is equal to the total momentum after the collision. Since the cube is stationary, its momentum is zero. Therefore, the momentum of the ball before the collision is equal to the momentum of the ball after the collision.

According to the principle of conservation of kinetic energy, the total kinetic energy before the collision is equal to the total kinetic energy after the collision.

Let's consider the different cases and determine the corresponding relationships between the final velocity v of the ball and the masses of the ball and the cube.

Case 1: The mass of the ball is several times smaller than the mass of the cube.

In this case, the ball will rebound backward with a final velocity v that is practically equal to the initial velocity v0. This is because the mass of the ball is much smaller than the mass of the cube, so the ball will experience a larger change in velocity compared to the cube. Therefore, the correct answer is A) The ball rebounds backward, and v is practically equal to v0.

Case 2: The mass of the ball is equal to the mass of the cube.

In this case, the ball will come to a stop after the collision, and its final velocity v will be equal to 0. This is because the masses of the ball and the cube are equal, so they will experience equal and opposite changes in velocity. Therefore, the correct answer is B) The ball comes to a stop, and v is equal to 0.

Case 3: The mass of the ball is much larger than the mass of the cube.

In this case, the ball will rebound backward with a final velocity v that is less than the initial velocity v0. This is because the mass of the ball is much larger than the mass of the cube, so the ball will experience a smaller change in velocity compared to the cube. Therefore, the correct answer is C) The ball rebounds backward, and v is equal to 0.5 * v0.

Case 4: The mass of the ball is several times larger than the mass of the cube.

In this case, the ball will rebound backward with a final velocity v that is less than the initial velocity v0. This is because the mass of the ball is larger than the mass of the cube, so the ball will experience a smaller change in velocity compared to the cube. Therefore, the correct answer is C) The ball rebounds backward, and v is equal to 0.5 * v0.

Case 5: The mass of the ball is much smaller than the mass of the cube.

In this case, the ball will rebound backward with a final velocity v that is practically equal to the initial velocity v0. This is because the mass of the ball is much smaller than the mass of the cube, so the ball will experience a larger change in velocity compared to the cube. Therefore, the correct answer is A) The ball rebounds backward, and v is practically equal to v0.

Based on the analysis above, the correct answer is either A) The ball rebounds backward, and v is practically equal to v0 or C) The ball rebounds backward, and v is equal to 0.5 * v0. The correct answer depends on the relative masses of the ball and the cube.

Let's consider the given options for the masses of the ball and the cube:

1) The mass of the ball is several times smaller than the mass of the cube. 2) The mass of the ball is equal to the mass of the cube. 3) The mass of the ball is much larger than the mass of the cube. 4) The mass of the ball is several times larger than the mass of the cube. 5) The mass of the ball is much smaller than the mass of the cube.

Comparing the given options with the analysis above, we can conclude that the correct answer is either A) The ball rebounds backward, and v is practically equal to v0 or C) The ball rebounds backward, and v is equal to 0.5 * v0.

Please note that the correct answer depends on the relative masses of the ball and the cube, which are not provided in the question.