Displacement
If an object moves, its position changes over time. The first step in describing motion is quantifying how much the position has changed. The corresponding physical quantity is called displacement.
Displacement
The displacement of a particle is the change in the position in some time interval.
In one dimension, if the initial position of the particle is (x_0\) and the final position is \(x,\) the displacement is defined as
\[\Delta x = x - x_0.\]
In three dimensions, if the initial position of the particle is \(\mathbf{r}_0\) and the final position is \(\mathbf{r},\) the displacement is defined as
\[\Delta \mathbf{r} = \mathbf{r} - \mathbf{r}_0.\]
Displacement is a vector that points from the initial position to the final position.
The SI unit of displacement is the metre.
\[\left[\Delta\mathbf{r}\right] = 1\,\mathrm{m}\]