Scalars vs. Vectors: Magnitude and Direction

Steps:

• Define scalar: A quantity with only magnitude, like mass or temperature.
• Define vector: A quantity with both magnitude and direction, like velocity or force.
• Identify key difference: Scalars lack direction; vectors include it.
• Match to choices: Option B states this precisely.

Why B is correct:

• By definition, vectors require direction for complete description (e.g., displacement arrow shows both length and path), while scalars need only a numerical value.

Why the others are wrong:

• A: Reverses the definitions—scalars have no direction.
• C: Incorrect; both have magnitude, but vectors add direction.
• D: Reverses the magnitude claim—both possess it, but scalars stop there.

Final answer: B