Question

Пуля массой 10 г попадает в дерево толщиной 10 см. имея скрасить 400 м/с. Пробив дерев, пуля вылетает со скоростью 200 м/с. Определите силу сопротивления, которую испытывает пуля, пробивая дерево?

Answer 1

Работа силы сопротивления равна изменению кинетической энергии пули:
 F*s=m*(V2^2-V1^2)/2
F=m*(V2^2-V1^2)/2*s=0,01*(4-16)*10^4/2*0,1=-6000 H
Знак - указывает, что сила оказывает тормозящее действие на пулю

Answer 2

Calculation of Resistance Force Experienced by the Bullet

To determine the resistance force experienced by the bullet as it penetrates the tree, we can use the principle of conservation of momentum. The initial momentum of the bullet before hitting the tree is equal to its final momentum after exiting the tree.

The momentum of an object is given by the product of its mass and velocity. Therefore, we can write the equation:

Initial momentum of the bullet = Final momentum of the bullet

The initial momentum of the bullet can be calculated as the product of its mass and initial velocity:

Initial momentum = mass × initial velocity

The final momentum of the bullet can be calculated as the product of its mass and final velocity:

Final momentum = mass × final velocity

Since the mass of the bullet remains constant throughout the process, we can equate the two equations:

mass × initial velocity = mass × final velocity

Simplifying the equation, we can cancel out the mass:

initial velocity = final velocity

Therefore, the resistance force experienced by the bullet can be calculated by subtracting the initial velocity from the final velocity:

Resistance force = initial velocity - final velocity

Given that the initial velocity of the bullet is 400 m/s and the final velocity is 200 m/s, we can substitute these values into the equation:

Resistance force = 400 m/s - 200 m/s

Calculating the resistance force, we find:

Resistance force = 200 m/s

Therefore, the resistance force experienced by the bullet as it penetrates the tree is 200 m/s.

Please note that the units for the resistance force should be in Newtons (N), not meters per second (m/s). However, since the question does not provide any information about the time of impact or the duration of the force, we cannot calculate the exact force in Newtons. We can only determine the change in velocity, which is 200 m/s.