Answer: a) 2r
The movement of a body following a circular path is called a circular motion.
- The total distance measured between the start and ending points is known as displacement.
- The displacement may be easily estimated once the particle has covered half of the circle by measuring the distance between the beginning and final points.
After half-circle displacement = AB = OA + OB
- OA = r
- OB = r
∴ AB = r + r
AB = 2r
As a result, the displacement after completing a half-circle is 2r.