Question

as shown in the figure a child starting a journey from. O features to a first then Travels one quarter of a circle along a b and finally returns to a if the radius of the circle is R then find the total distance covered by the child
total displacement of the child

Answer 1

taking radius of the circle 'r'
Circumference of the circle= 2$\pi$r 
as it is covering 1/4 of the circumference of the circle ,
the distance covered will be = $\pi$r/2 along AB
Now, total distance is OA+AB+BO
OA=BO=r
 Pr/2 + r+r= 2r + $\pi$r/2
= (4$\pi$r+r)1/2

Now total displacement is '0' as its initial and final points are same i.e O.