Which of the following best describes the difference between $scalar$ and $vector$ quantities?

• A. Both $scalar$ and $vector$ quantities have neither magnitude nor direction.
• B. $Scalar$ quantities have only magnitude, while $vector$ quantities have both magnitude and direction.
• C. $Scalar$ quantities have both magnitude and direction, while $vector$ quantities have only magnitude.
• D. Both $scalar$ and $vector$ quantities have only direction.

Answer: (B)

Verified step by step guidance

1. Understand that physical quantities can be classified into two main types: scalar and vector quantities.
2. Recall that scalar quantities are described completely by a single number representing their magnitude (size or amount) alone, without any direction. Examples include temperature, mass, and time.
3. Recognize that vector quantities require both a magnitude and a direction to be fully described. Examples include displacement, velocity, and force.
4. Note that the key difference lies in the presence or absence of direction: scalars have magnitude only, while vectors have both magnitude and direction.
5. Therefore, the best description is that scalar quantities have only magnitude, while vector quantities have both magnitude and direction.