How is momentum defined in physics?

Momentum in physics is defined as the product of an object's mass and its velocity. This relationship illustrates how momentum is a vector quantity, which means it has both magnitude and direction.

When we multiply the mass of an object (a scalar quantity) by its velocity (which has direction), we obtain momentum, also known as linear momentum. This concept is fundamental in understanding how objects move and interact. For instance, a more massive object or an object moving at a higher speed will possess greater momentum, thus requiring more force to change its state of motion.

The other definitions provided do not accurately represent the concept of momentum. The division of mass by velocity results in a different quantity that does not relate to momentum. The product of force and the duration of application describes impulse, which is related but distinctly different from momentum. Lastly, the change in velocity over time describes acceleration, which again, does not equate to momentum. Understanding momentum is crucial in analyzing collisions and various dynamics in physics, as it is conserved in isolated systems.