A person is running along a circular track of area 625 m^{2} (=22/7) with a constant speed. Find the displacement in 15 seconds if he has to complete the race in 30 sec.

A person is running along a circular track of area 625 m^{2} (=22/7) with a constant speed. Find the displacement in 15 seconds if he has to complete the race in 30 sec.