Can displacement be negative?

1 Answer
Apr 28, 2017

Answer:

Someone has asked for a real life example of negative displacement, so here is one below.

Explanation:

Displacement can be negative because it defines a change in position of an object while carefully monitoring its direction.

For our example the object we will consider is you. If you leave your present position and walk down a hallway to get a drink and you walk #6m# to where the drink is located, your displacement is #6m# in the #h# (hallway) direction. We will take this first trip as the positive direction

Then you walk back towards your original location in the #-h# opposite direction. But Surien calls you to her office which is #15m# further past your office. It is still in the direction #-h# opposite the drink location.

Your displacement is now #6m-6m-15m=-15m# in the #h# direction. Notice both displacements had to be subtracted from the #+h# of your first trip because both were in the #-h# direction from it.

Then you return to your original location.
Now your total displacement is:

#6m-6m-15m+15m=0m# in the #h# direction.

Because of positive and negative displacement vectors, you have essentially gone nowhere. You can verify this by looking around. You are back at your original location.

While accomplishing this feat, you have managed to cover a distance of #6m+6m+15m+15m=42m#

Time for another drink....