Question

An insect trapped in a circular groove of radius $12cm$ moves along the groove steadily and completes $7$ revolutions in $100s$. What is the linear speed of the motion:-

• A. $2.3cm/s$
• B. $5.3cm/s$
• C. $0.44cm/s$
• D. $noneofthese$

Answer 1

The correct option is B $5.3cm/s$

$r=12cm;n=\frac{7}{100}0.07rev/s$
$\because \omega =2\pi n\therefore v=\omega r=2\pi nr$
$v=2\times \frac{22}{7}\times \frac{7}{100}\times 12=5.28\cong 5.3cm/s$