Momentum is a fundamental concept in physics that describes the motion of an object. It is defined as the product of an object's mass and its velocity. Mathematically, momentum (p) can be expressed as p = m * v, where m represents mass and v represents velocity. The SI unit for momentum is kilogram-meter per second (kg·m/s).

Momentum plays a crucial role in physics as it quantifies the amount of motion an object possesses. The greater the momentum of an object, the harder it is to stop or change its motion.

To better understand the concept of momentum, let's consider a couple of everyday scenarios. Imagine a small car and a large truck moving at the same speed. Despite having the same velocity, the truck has a higher momentum due to its larger mass. Similarly, if a tennis ball and a bowling ball are thrown with the same speed, the bowling ball will have a larger momentum because it has a greater mass. Thus, momentum accounts for both the mass and velocity of an object.