Q.
A cylindrical piece of cork of density ρ of base area A and height h floats in a liquid of density ρ′. The cork is slightly depressed and then released. The time period of oscillation of the cork is
At equilibrium while floating,
Weight = Upthrust i.e mg=(ρ′Ay0)g where y0 is the immersed length of the cork ⇒(ρAh)g=(ρ′Ay0)g
When the cork is further immersed by y and released, then F=(mg)−ρ′A(y+y0)g=ρ′Ay0g−ρ′Ayg−ρ′Ay0g F=−(ρ′Ag)y ⇒T=2πkm=2πρ′AgρAh =2πgρ′hρ