# Question #f8f00

Jul 12, 2015

Here are some examples of that.

#### Explanation:

Displacement is a vector quantity which expresses that total change in position that results from a particular motion made by an object.

Displacement takes into account the direction in which a movement takes place. As you would imagine, the only two important points when determining an object's displacement are the start point and finish point.

Any other point covered during the object's motion is not important when determining displacement.

So, in order for an object to have zero displacement, its start point and finish point must be the same.

If an object starts its movement from point $A$ and ends its movement in point $A$, then it had zero displacement.

A very good example is a runner that runs on a cicular track. If the runner starts and finishes the race at the same point, then its overall displacement will be zero. This is true regardless of how many complete laps the runner manages to finishes.

Likewise, if you travel in a straight line from point $A$ to point $B$, then turn around and head back to point $A$, your net displacement will again be zero. Another example would involve throwing an object straight up from ground level. On its way up, the object will travel for a distance of $h$ meters.

On its way down, the object will again travel for a distance of $h$ meters, this time in opposite direction. This is exactly the same principle as the one shown above with the car, only this time the movement in vertical, not horizontal. The object starts from ground level and ends up on ground level, so its displacement is zero.