Vectors have magnitude and direction

Steps:

• Define a vector as a quantity with both magnitude and direction, unlike scalars with only magnitude.
• Examine each option: distance measures length without direction.
• Force requires both strength and direction to describe its effect.
• Mass is a measure of matter without direction; speed is magnitude of velocity without direction.

Why B is correct:

• Force is a vector because it has magnitude (strength) and direction, as defined in Newton's second law, F = ma, where direction determines the acceleration vector.

Why the others are wrong:

• A. Distance is a scalar, representing total path length without direction.
• C. Mass is a scalar, quantifying inertia without direction.
• D. Speed is a scalar, the magnitude of velocity without specifying direction.

Final answer: B