# Distance vs displacement

Show/Hide Sub-topics (Speed, Velocity and Acceleration | O Level)

Distance travelled by an object is the length of path taken.

Displacement is the shortest distance from the initial to the final position of an object.

## Distinguishing Between Distance and Displacement

If you have problems grasping the difference in concept of displacement and distance travelled, please study the example below.

### Consider the diagram above:

Difference between distance and displacement: If an object started travelling from B to C and ends at D, distance travelled is BC + CD. Displacement is BD.

Displacement can be ZERO: If the object started travelling from B to C to D and ends at B, distance travelled is BC + CD + DB. Displacement is ZERO. (The object ends at the same place it started)

Displacement can be NEGATIVE: If the object travels from B to A, the displacement is negative. By CONVENTION, the direction towards the right and top are positive. A way to remember: Go right = positive, go left = negative.

## Examples

### Ali walked 1 km to the North, then 1 km to the East and followed by 1 km to the South. What is the distance covered by Ali? What is his final displacement?

Distance: $1 + 1 + 1 = 3 \, \text{km}$

Displacement: 1 km east of starting point.

### A car travelled from point O to D along the curved path OABCD. What is (a) the distance travelled by the car, and (b) the displacement of the car?

The distance travelled by the car is OABCD.

The displacement of the car from point O is OD (to the right of O).

### 9 thoughts on “Distance vs displacement”

1. i still dont understand how to calculate the displacement

2. It is negative because it is descending.

3. Hi!! can u send me note via email i am interested in physics

4. i don’t get the fomular that is used to find displacement!! thumbs up!!

• the shortest path it takes to go from starting point to the destination example: sara goes to south 2 km (A) then 2 km to east (B) and 2 km to north (C) (draw a diagram for better understanding) 2 km + 2 km + 2 km = 6 km that’s our distance for displacement the shortest way to reach her destination (C) was to go directly from A to C that means 2 km (one path to reach one path takes 2 km).