Answer
(a) The distance traveled = 130m.
The displacement: $\Delta x=100m$
(b) The distance traveled = 260m.
The displacement: $\Delta x=0$
Work Step by Step
(a) The distance traveled $=15m+100m+15m=130m$.
Notice that, after running from point A to point B the jogger has completed half of a complete circuit of the track.
Now, assuming that the point A is at the origin ($x=0$) of the x axis,
$x_{i}=0$ and $x_{f}=100m$.
$\Delta x=x_{i}-x_{f}=100m-0=100m$.
(b) The distance traveled $=100m+30m+100m+30m=260m$.
In a complete circuit of the track, the initial position and the final position are the same: $x_{i}=x_{f}$. So: $\Delta x=x_{f}-x_{i}=0$.
