A uniform cylinder of length L and mass M having cross-sectional area A is suspended, with its length vertical, from a fixed point by a massless spring, such that it is half submerged in a liquid of density at equilibrium position. The extension x0 of the spring when it is in equilibrium is?

Let k be the spring constant and let x<sub>o</sub> be the extended length of the spring when it is in the equilibrium position.

In equilibrium,

Kx<sub>o</sub>+F<sub>B</sub>=Mg

kx<sub>o</sub>+σL/2 AG = Mg

x<sub>o</sub>=Mg/k(1-σLA/2M)