Answer
$0$
Work Step by Step
(e)
Using the same coordinate system defined in part (a),
the initial position of the hand is now : $ \vec{r_{1}}=(10cm)\hat{j}$,
and the final position is : $ \vec{r_{2}}=(10cm)\hat{j},$
So, $\Delta\vec{r}=\vec{r}_{2}-\vec{r}_{1}=0$
(Makes sense because after a full hour, the final position of the tip is the same as it was before the motion)
