Question

13) A body covers an are of a circle of radius 'r,
subtending an angle of 120° at the centre of the
circle. The magnitude of the displacement of the
body is

Answer 1

Answer:

Note in diagram

Displacement = 2x = ?

Now

$\sin(60) = \frac{x}{r} \\ \\ x = r \times \frac{ \sqrt{3} }{2} = \frac{ \sqrt{3} r}{2}$

So displacement

$= 2x = 2 \div \frac{ \sqrt{3} r}{2} = \sqrt{3} \: r$