(Solved): A hydrometer floats in a liquid of density as shown in the figure on the right. It is slightly d ...

A hydrometer floats in a liquid of density $?$ as shown in the figure on the right. It is slightly depressed from its normal position of equilibrium and periodic motion about the equilibrium results. Show that the period of oscillations is given by $T=2?\sqrt{\frac{M}{gA?}},$ where $M$ is the mass of the hydrometer and $A$ is the cross sectional area.