When a bullet is fired from a gun

When a shot is fired from a gun, the gun recoils. This is explained by :

If a bullet of 50 g is fired fro a gun of 10 kg. then what will be the projection velocity of the gun if velocity of the bullet is 400 m//s ? What do you mean by linear momentum?

A 10g bullet is fired from a rifle horizontally into a 5kg block of wood suspended by a string and the bullet gets embedded in the block. The impact causes the block to swing to a height of 5 cm above its initial level. Calculte the velocity of the bullet.

A shot is fired from a gun. What will be the changes in momentum and kinetic energy ?

What is a projectile ? Obtain an expression for: maximum height , time of flight and the horizontal range when a projectile is fired at an angle theta with the horizontal.

A machine gun fires bullets at the rate of 180 shots per minute. Each bullet is of mass 20 g and moves with a velocity of 1 km cdot s^(-1) . After colliding perdicularly with a steel plate, the bullets rebound with half the incident speed. What will be the force required to keep the steel plate in position?