Momentum, also known as linear momentum, is a physical quantity that is equal to the product of an object's mass and velocity.
$$\vec{p}=m\vec{v}$$
where,
m— mass of the object
v— velocity of the object.
The unit of momentum is kilogram-meter per second (kg·m/s).
The law of conservation of momentum states that the total momentum of any system of objects is conserved if no external forces act on that system.
$$m_1 \vec{u}_1 + m_2 \vec{u}_2 = m_1 \vec{v}_1 + m_2 \vec{v}_2$$
The law of conservation of momentum applies to both Newtonian mechanics, special relativity, and quantum mechanics. It holds independently of the law of conservation of energy.
The law of conservation of angular momentum states that when there is no external torque present in the system, then its total angular momentum remains conserved.
Impulse is the change in momentum of an object.
$$\vec{F}_t=\Delta \vec{p}=\Delta m\vec{v}$$