The diameter of a solid disc is 0.5 m and its mass is 16kg. What torque is required to increase its angular velocity from zero to 120 revolutions per minute in 8 seconds?

Options

A. `(pi//4Nm)`
B. `pi//2Nm`
C. `pi//3Nm`
D. `piNm`

Answer

A

Explanation

Here `omega=omega_(0) +alphat`
or `omega-omega_(0)=alphat=(r )/(I)t`
`2pin=(tauxx2)/(MR^(2)).t`
Thus `tau=(pinxxMR^(2))/(t)`
=`(pixx2xx16xx(0.25)^(2))/(8)=pi//4Nm`