A rectangular block of mass m and area of cross-section A floats in a liquid of density ρ. If it is given a small vertical displacemnet from equilibrium it undergoes oscillation with a time period T. Then

Let the body be depressed by distance x from its equilibrium position. The extra upthrust created is x ρAg which applies to whole body. If a be acceleration created then,xρAg=−mga⇒a=−ρAmx​ Since, acceleration ∝x . So, it is equation of S.H.M. ​ ∴ ω2=ρAm⇒T=2πmρA​⇒T∝1A