A wheel of radius 1 meter rolls forward half a revolution on a horizontal ground. The magnitude of the displacement of the point of the wheel initially in contact with the ground is
Horizontal distance covered by the wheel in half revolution = π R
So the displacement of the point which was initially in contact with ground = AA′=√(πR)2+(2R)2
=R√π2+4=√π2+4 (As R=1 m)