Question

Which one of the following is a vector quantity?

• A. Distance
• B. Displacement
• C. Position
• D. Speed

Answer 1

Answer: (B), (C)

Position

Vector quantity:

1. Quantities that need both magnitude and direction to describe them are called vector quantities.
2. Examples: Displacement, velocity, force, area, etc.

A: Distance

1. It is the actual length of the path covered by a body.
2. Distance can be identified by only magnitude. So, it is considered a scalar quantity.

B: Displacement

1. It is the shortest path covered by an object between its final and initial position.
2. Since to determine the displacement, we have to specify the direction of initial and final positions.
3. Displacement is considered a vector quantity because it needs both the magnitude as well as the direction.

C: Position

1. Position is defined as the location of a body.
2. Position is a vector quantity as it specifies the direction of the location of a body.

D: Speed

1. Speed is the distance covered by an object in a given time.
2. $Speed=\frac{dis\tan ce}{time}$
3. Since speed is related to distance covered and distance is a scalar quantity. So, speed is also a scalar quantity.

Thus, displacement and position both are vector quantities.

Hence, options (b) and (c) are correct.