An insect trapped in a circular groove of radius 12 cm moves along the groove steadily and completes 7 revolution in 100 s. The linear speed of the insect is

Here, r = 12 cm

             Frequency v = $\frac{7}{100}\mathrm{Hz}$

The angular speed of the insect is

$\omega = 2\pi v = 2\pi \times \frac{7}{100} = 0.44 rad s^{-1}$

The linear speed of the insect is

v = $\mathrm{\omega r} = 0.44\times 12 = 5.3$$\mathrm{cm} {\mathrm{s}}^{-1}$