A massless string is wrapped around a uniform solid cylinder of mass `30kg` and radius `0.20m`. One end of the string is attahed to the cylinder and the free end is pulled tangentially by a force that maintains a constant tension of `3.0` N. Find a) the angular acceleration and b) The angular speed of the cylinder `2.0` s after the force is applied to the cylinder at rest.

Explanation

(a) We know that `tau=Ialpha`
`F.r=Ialpha` `F.r=(mr^(2))/(2).alpha`
`alpha=(2F)/(mr)=(2xx3)/(30xx0.2)=1rad//s^(2)`
(b) `omega_(2)-omega_(1)=alphat` `:.omega_(2)=alphat`
angular speed after 2 sec, `omega_(2)=1xx2=2rad//sec`