In introductory physics, which statement best defines the linear momentum of an object?

• A. Momentum is a vector equal to mass times velocity: $p=mv$.
• B. Momentum is the rate of change of position with time: $p=\frac{dx}{dt}$.
• C. Momentum is the product of force and time: $p=Ft$.
• D. Momentum is a scalar equal to mass times speed: $p=mv$, where $v$ is speed only.

Answer: (A)