A person runs along a circular path of radius 5 m. If he completes half of the circle, find the magnitude of the displacement vector, How far the person ran ?

After completing half circle, the person will reach to diagonally opposite point.

displacement = length of the diameter = $\left|\overrightarrow{\mathrm{AB}}\right|=2\times \mathrm{radius} = 2\times 5=10 \mathrm{m}$

distance traveled = path length = $=l\left(arc \stackrel{⏜}{\mathrm{ACB}}\right)=\mathrm{\pi }\times \mathrm{radius} = 5\mathrm{\pi } \mathrm{m}$