A wheel having moment of interia `2 kgm^(-2)` about its axis, rotates at 50 rpm about this axis. The angular retardation that can stop the wheel in one minute is

Options

A. `(pi)/(36)"rad s"^(-2)`
B. `(pi)/(18)"rad s"^(-2)`
C. `(pi)/(72)"rad s"^(-2)`
D. `(pi)/(9)"rad s"^(-2)`

Answer

A

Explanation

The initial angular velocity `="50 rpm"=(5pi)/(3)"rad s"^(-1)`
Using, `omega=omega_(0)+alphat`
`alpha=(omega-omega_(0))/(t)=(0-(5pi)/(3))/(6)"rad s"^(-2)=-(pi)/(36)"rad s"^(-2)`