Distance vs Displacement

Understanding Distance and Displacement

In physics, distance and displacement are two important concepts used to describe motion. Although they are related, they have distinct meanings.

• Distance is the total path length traveled by an object, regardless of direction. It is a scalar quantity, meaning it only has magnitude.
• Displacement is the shortest straight-line distance from the initial to the final position of an object. It is a vector quantity, meaning it has both magnitude and direction.

Key Differences

Distance	Displacement
Scalar quantity	Vector quantity
Only magnitude	Magnitude and direction
Always positive	Can be positive, negative, or zero
Depends on the path taken	Independent of the path taken

Graphical Representation

Distance and displacement can be represented on a graph. A distance-time graph shows how far an object has traveled over time, while a displacement-time graph shows the change in position over time.

Example

Imagine you walk 3 km east, then 4 km west. What is your distance and displacement?

• Distance: Total path traveled = 3 km + 4 km = 7 km
• Displacement: Final position relative to the start = 3 km - 4 km = -1 km (1 km west)