Question

a perdon runs along a circular path of radius 5m if he completes half of the circle find the magnitude of the displacement vector, how far the person ran

Answer 1

Displacement is the distance between the initial point and the final point, while distance is the length of the entire path travelled.
According to your question; the distance travelled by the man is basically the curved path of half a semi circle, viz. 2$\pi$R, where R is the given radius = 5m.
Therefore, the distance would be 2 x $\pi$ x 5m = 10 $\pi$m.
Whereas, the displacement would be R x 2 (since he covered a semi circle) = 5m x 2 = 10m
Therefore, displacement  = 10$\pi$mdistance  = 10m
Hope this helped! <3