# When fired from a pistol, a bullet of mass m flies out and moves at a speed v. What modulus of momentum

When fired from a pistol, a bullet of mass m flies out and moves at a speed v. What modulus of momentum does a pistol acquire after firing if its mass is 100 times the mass of a bullet? (it seems to me 0) A cart with a mass of 2 kg, moving at a speed of 3 m / s, collides with a stationary cart with a mass of 4 kg and engages with it. What is the speed of both carts after interaction? What is the change in momentum of the body if it is acted upon by a force of 15 N for 5 s?

1) According to the law of conservation of momentum, the pistol will acquire an impulse equal to the impulse of the bullet (does not depend on the mass of the pistol:

p = m * v, where m is the mass, v is the speed of the bullet.

2) Let us write the law of conservation of momentum for a system consisting of two carts:

m1 * v1 = V * (m1 + m2), where m1 and m2 are the masses of the bogies, v1 is the speed of the first bogie before interaction, V is the speed of the bogies after interaction.

V = m1 * v1 / (m1 + m2).

V = 2 * 3 / (2 + 4) = 1 m / s.

Answer: the required speed is 1 m / s. One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.