Question

A particle is moving in a circular path of radius r, the displacement after half a circle would be

• A. $Zero$
• B. $\pi r$
• C. $2r$
• D. $2\pi r$

Answer 1

The correct option is C

$2r$

Given, radius of the circle is 'r'.

Circumference of circle $=2\pi r$
Distance travelled after half a circle
$=\frac{2\pi r}{2}=\pi r$

But displacement is the shortest path between the final position and initial position.
In this case, it is the diameter, which is 2r.