Q.

A cylindrical block of mass M and area of cross section A is floating in a liquid of density ρ and with its axis vertical. When depressed a little and released the block starts oscillating. The period of oscillation is _________.             [2026]

1 πρAMg  
2 2πρAMg  
3 π2MρAg  
4 2πMρAg  

Ans.

(4)

At equilibrium

ρAhg=Mg

After displacing by x,

Ma=-ρA(h+x)g+Mg

Ma=-ρAhg-ρAxg+Mg

Ma=-ρAxg

a=(-ρAgM)x

on comparing with,

a=-ω2x

ω=ρAgM

T=2πω=2πMρAg