GMAS Physical Science Practice Test

Momentum measures how hard it is to stop a moving object, and it comes from combining how much stuff there is with how fast it’s moving. The formula p = m v captures that idea: momentum equals mass times velocity. Since velocity is a vector, momentum also has a direction—the same as the motion’s direction—which helps explain why momentum changes when velocity changes and why impulses affect momentum.

The units check out as kilograms times meters per second (kg·m/s). If an object isn’t moving, its velocity is zero, so its momentum is zero. If either mass or velocity increases, its momentum increases accordingly.

The other ideas describe different things: one equation relates energy to mass, another links force to acceleration, and the mistaken form would pair mass with acceleration, which doesn’t describe momentum.