$Which\; of\; the\; following\; must\; be\; included\; with\mathrm{magnitude}to\; fully\; represent\; a\mathrm{vector}quantity?$

• A. $\mathrm{Direction}$
• B. $\mathrm{Mass}$
• C. $\mathrm{Temperature}$
• D. $\mathrm{Speed}$

Answer: (A)

Verified step by step guidance

1. Understand that a vector quantity is defined by both its magnitude and another key property.
2. Recall that magnitude alone describes the size or amount of a quantity, but does not specify its orientation in space.
3. Recognize that to fully represent a vector, you must include the direction in which the quantity acts, as vectors have both magnitude and direction.
4. Note that scalar quantities, such as mass, temperature, and speed, have only magnitude and no direction, so they do not fully describe vectors.
5. Conclude that the essential component to pair with magnitude for a complete vector description is direction.