In physics, momentum is a measure of an object's motion. It is defined as the product of an object's mass and its velocity.

To explain it simply, think of momentum as the "oomph" that an object has when it's moving. An object with a lot of momentum is difficult to stop or change its direction, while an object with low momentum is easy to stop or change its direction.Mathematically, momentum (p) is calculated as the product of an object's mass (m) and velocity (v):p = m * vwhere p is the momentum, m is the mass, and v is the velocity.

It's important to note that momentum is a vector quantity, which means it has both magnitude and direction. The direction of an object's momentum is the same as its direction of motion.

The principle of conservation of momentum states that the total momentum of a system of objects is conserved (stays the same) unless an external force acts on the system. This means that if two objects collide, the total momentum of the system before the collision is equal to the total momentum of the system after the collision (assuming no external forces).

In summary, momentum is a measure of an object's motion and is calculated as the product of its mass and velocity. It has both magnitude and direction and is conserved unless an external force acts on the system.