Q. 4.8 Three girls skating on a circular ice ground of radius start from a point on the edge of the ground and reach a point diametrically opposite to following different paths as shown in Fig. 4.20. What is the magnitude of the displacement vector for each? For which girl is this equal to the actual length of path skate?
The displacement vector is defined as the shortest distance between two points which particle had covered.
In this case, the shortest distance between these points is the diameter of the circular ice ground.
Thus, Displacement = 400 m.
Girl B had travelled along the diameter so path travelled by her is equal to the displacement.