Question

A body is moving along a circular path of radius r. what will be the distance and replacement of the body when it completes half a revolution.​

Answer 1

Answer:

Where r is radius of circle. When particle covers half the circle, it is diametrically opposite to the starting point of its motion. Therefore shortest distance is equal to diameter of circle or 2× r is a displacement. Hence displacement is equal to diameter or 2 times the radius of circle.

Answer 2

Explanation:

Let us assume that a body starts from point A of a circular path to point B. Here it covers half of the revolution of the circular path. If it return backs to its initial point i.e. A then it covers the one complete revolution.

Distance covered in one round = Circumference of circle.

And circumference of circle = 2πr

Given that, the radius of circular path is 'r'.

Distance covered in half revolution = (Circumference of circle)/2

= (2πr)/2 = πr

Therefore, distance covered by the body is πr.

Whereas, Displacement is defined as the shortest path covered between initial and starting points.

So, Displacement of the body = 2 × Radius of the circular track or path.

Therefore, displacement of the body is 2r.