[" Q."49" A wooden rod of a uniform cross section and of length "],[120cm" is hinged at the bottom of the tank which is "],[" filled with water to a height of "40cm" .In the equilibrium "],[" position,the rod makes an angle of "60^(@)" with the vertical."],[" The centre of buoyancy is located on the rod at a "],[" distance (from the hinge) of "40cm],[[" (c) "60cm," (d) "75cm]]