Question

A body moves along a circular path of radius 20 cm. After it completes one fourth revolution, the ratio of distance travelled to its displacement is

Answer 1

Distance covered =
$\frac{2\pi r}{4}$
Displacement =
$\sqrt{{r}^{2} + {r}^{2} } = r \sqrt{2}$
Ratio between distance and displacement
$= \frac{2\pi r}{4} \div r \sqrt{2 } = \frac{2\pi r}{4} \times \frac{1}{r \sqrt{2} } = \frac{\pi}{2 \sqrt{2} } = \frac{11}{7 \sqrt{2} } = \frac{11 \sqrt{2} }{14}$