Which of the following pairs of physical quantities is made up of vectors?

Analyze the question: We need the pair in which both quantities are vectors (they have magnitude and direction).

Concept:

• Vector quantities have both magnitude and direction. Examples: displacement, velocity, acceleration, force, momentum, weight.
• Scalar quantities have magnitude only. Examples: speed, distance, mass, length, time, energy.

Step-by-step check:

• A. Speed and displacement: Speed is a scalar and displacement is a vector. Not both vectors. ✗
• B. Mass and force: Mass is a scalar and force is a vector. ✗
• C. Displacement and acceleration: Displacement is a vector, since it is distance in a given direction. Acceleration is a vector, since it is the rate of change of velocity in a given direction. Both are vectors. ✓
• D. Momentum and length: Momentum is a vector (mass × velocity), but length is a scalar. ✗

Answer: Option C, displacement and acceleration.

Tip: Ask whether you can sensibly add "towards the north" (or any direction) to the quantity. "5 m north" (displacement) and "2 m/s² north" (acceleration) make sense, but "5 kg north" (mass) or "5 m/s north" for speed does not. Remember the common scalar-vector pairs: distance vs displacement, and speed vs velocity.