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 cms^(-1)`
B. `5.3 cms^(-1)`
C. `6.3 cms^(-1)`
D. `7.3 cms^(-1)`

Answer 1

Correct Answer - b
Here, r=12 cm
Frequency `V=7/100Hz`
The angular speed of the insect is
`omega=2piv=2pixx7/100=0.44 rads^(-1)`
The linear speed the insect is
`v=omegar=0.44xx12=5.3cms^(-1)`