A non uniform cylinder of mass `m`, length `l` and radius `r` having its C.O.M at a distance `(l)/(4)` from centre and lying on axis of cylinder . The cylinder is kept in a liquid of unifrom density `rho`. The moment of inertia of the rod about C.O.M is I. The angular acceleration of point A relative to point B just after the rod is released from position shown in figure is .

Options

A. `(pirhogl^(2)r^(2))/(2I)`
B. `(3pirhogl^(2)r^(2))/(4I)`
C. `(pirhogl^(2)r^(2))/(I)`
D. `(pirhogl^(2)r^(2))/(4I)`

Answer

D

Explanation

`F_("Buoyancy")=piR^(2)lrhog`

T orque `=(pir^(2)l^(2)rhog)/(4)`
`alpha=(pi^(2)l^(2)rhogr^(2))/(4I)`