Question

An insect trapped in circular groove of radius 12 cm moves along the groove steadily and completes 7 revolutions in 100s. The linear speed of the insect is
A. 4.3 cm `s^(-1)`
B. 5.3 cm `s^(-1)`
C. 6.3 cm `s^(-1)`
D. 7.3 cm `s^(-1)`

Answer 1

Correct Answer - B
Here, r=12 cm, frequency, `v=(7)/(100)rps`
The angular speed of the insect is
`omega=2piv=2pixx(7)/(100)=0.44rads^(-1)`
The linear speed of the insect is `v=omegar=0.44xx12=5.3cms^(-1)`