Define and explain displacement.

(N/A) The change in position of a particle in a particular interval of time is called displacement. Let $x_{1}$ and $x_{2}$ be the positions of an object at time $t_{1}$ and $t_{2}$.
Its displacement,denoted by $\Delta x$ in time $\Delta t = (t_{2} - t_{1})$,is given by the difference between the final and initial positions.
$\Delta x = x_{2} - x_{1}$
We use the Greek letter delta $(\Delta)$ to denote the change in a quantity.
If $x_{2} > x_{1}$,$\Delta x$ is positive; and if $x_{2} < x_{1}$,then $\Delta x$ is negative.
Displacement has both magnitude and direction.
In one-dimensional motion,there are only two directions (backward and forward,upward and downward) in which an object can move.
These two directions can easily be specified by $+$ and $-$ signs.
For example,the displacement of the car in moving from $O$ to $P$ is:
$\Delta x = x_{2} - x_{1} = (+360 \ m) - 0 \ m = +360 \ m$
The displacement has a magnitude of $360 \ m$ and is directed in the positive $x$-direction as indicated by the $+$ sign.
Similarly,the displacement of the car from $P$ to $Q$ is $240 \ m - 360 \ m = -120 \ m$. The negative sign indicates the direction of displacement.