Which equation defines momentum?

Which equation defines momentum?

• A. Force × time
• B. Mass × velocity; resists stopping
• C. Velocity × distance
• D. Mass × acceleration

Answer: (B)

Momentum is the quantity of motion of an object, representing how difficult it is to bring the object to a stop. It is defined as the product of an object's mass and its velocity, and it has the same direction as the velocity. This means heavier objects or faster ones have more momentum, and their motion is harder to arrest. That’s why the best description is mass times velocity with a note that it resists stopping. The other expressions refer to different concepts: force times time is impulse, which changes momentum; velocity multiplied by distance isn’t a standard measure of motion; and mass times acceleration is force (the cause that changes momentum), not momentum itself.

Momentum is the quantity of motion of an object, representing how difficult it is to bring the object to a stop. It is defined as the product of an object's mass and its velocity, and it has the same direction as the velocity. This means heavier objects or faster ones have more momentum, and their motion is harder to arrest.

That’s why the best description is mass times velocity with a note that it resists stopping. The other expressions refer to different concepts: force times time is impulse, which changes momentum; velocity multiplied by distance isn’t a standard measure of motion; and mass times acceleration is force (the cause that changes momentum), not momentum itself.