Question

Горизонтально летящая пуля массой 10г попала в лежащий на гладкой горизонтальной поверхности деревянный брусок массой 500г и застряла в нем. Какой была скорость пули, если брусок после выстрела приобрел скорость 10м/с?

Answer 1

Дано:
m1 = 10г (в данном случае массу можно не переводить в килограммы)
m2 = 500г
V = 10 м/с

Найти: Vп

Решение:
По закону сохранения импульса:
m1 * Vп + m1 * Vп = m1 * Vп` + m2 * Vб

Т.к. брусок до выстрела находила в покое, значит Vп = 0
И когда пуля попала в брусок, они стали иметь одинаковую массу и приобрели скорость 10 м/с

m1 * Vп + 0 = V(m1 + m2)
m1 * Vп = V(m1 + m2)
Vп = V(m1 +m2)/m1
Vп = 10 (500+10)/10 = 10 * 510/10= 5100/10 = 510 м/с

Answer 2

Calculation of Bullet Velocity

To determine the velocity of the bullet, we can use the principle of conservation of momentum. The momentum before the bullet hits the wooden block is equal to the momentum after the bullet becomes embedded in the block.

The momentum of an object is calculated by multiplying its mass by its velocity. Let's denote the mass of the bullet as m1 and the mass of the wooden block as m2. The initial velocity of the bullet is denoted as v1, and the final velocity of the bullet and the block together is denoted as v2.

According to the principle of conservation of momentum, we can write the equation:

m1 * v1 = (m1 + m2) * v2

Given the following values: - Mass of the bullet (m1) = 10 g = 0.01 kg - Mass of the wooden block (m2) = 500 g = 0.5 kg - Final velocity of the bullet and block (v2) = 10 m/s

We can rearrange the equation to solve for the initial velocity of the bullet (v1):

v1 = (m1 + m2) * v2 / m1

Substituting the values into the equation:

v1 = (0.01 kg + 0.5 kg) * 10 m/s / 0.01 kg

Calculating the result:

v1 = 50.0 m/s

Therefore, the velocity of the bullet before it hit the wooden block was 50.0 m/s.