First lets define what is displacement?

Displacement is a vector quantity (which means that it has both magnitude and direction) and is the shortest distance between initial position and final position of an object.


xf is final position and x0 is initial position Δx is the total displacement

Let us understand displacement through examples.

  1. Suppose a car starts from point A and goes straight 5kms then turns right and goes straight 3km then turns right and again goes 5kms straight then stops at point B. What is the displacement ? It is just 3 km, that is the shortest distance between initial position and final position.

2. Suppose a cyclists starts on a circular track from point A and goes to point B on other end and stops. What is the displacement ?

The cyclist rides for 4 km and stops at point B. So the displacement will be 2r (radius) that is 2.54 km.

3. Now suppose you want to go for a shopping to near by market and come back to your home. So you started from your home and went to the market that is 4 km away, you had your shopping and you came back to your home and now you are standing the the same place where you had started for market. What is the displacement? Answer is zero, yes because your distance may be 8 km but displacement is zero because you came back to the same postion.

4. A person has to reach from Point A to Point B, but he can’t see the route directly so he starts walking and asking people about the direction, finally he reaches point B after 4 hours. Even though he walked for a long distance the displace he made from point A to B is just 10 Km because the shortest distance between point A and B was 10 km but he did not follow shortest distance because he was not knowing the route.

5. A helicopter starts flying from point A to point B as given in the following diagram. What will be displacement ? Displacement will be Δx = 6.403 km.