The concept of conservation of momentum is a fundamental principle in physics. It states that the total momentum of an isolated system remains constant if no external forces act on it. This principle is derived from Newton's third law of motion, which states that for every action, there is an equal and opposite reaction.

Momentum, denoted by 'p', is the product of an object's mass and its velocity. The equation for calculating momentum is:

p = m * v

Where 'p' is the momentum, 'm' is the mass of the object, and 'v' is its velocity.

To understand the concept of conservation of momentum, let's take an example of a collision between two objects. Consider a scenario where a ball is moving with a certain velocity and collides with another stationary ball of the same mass. According to the conservation of momentum, the total momentum before the collision is equal to the total momentum after the collision.

For instance, if the moving ball has a momentum of 10 kg·m/s, the stationary ball has zero momentum. After the collision, the moving ball may lose some momentum, resulting in a new velocity, while the stationary ball gains momentum and starts moving in the opposite direction. However, the total momentum remains constant at 10 kg·m/s.

This fundamental principle of conservation of momentum has various applications in physics, such as analyzing the outcomes of collisions, understanding the behavior of rocket propulsion, and studying the motion of celestial bodies.