Mechanical Properties of Matter

The Bulk of Ethanol, Mercury and water are given as $$0.9, 25$$ and $$2.2$$ respectively in units of $$10^8 Nm^{-2}.$$ For a given value of pressure, the fractional compression in volume is $$\triangle V/V$$. Which of the following statements about $$\triangle V/V$$ for these three liquids is correct? 
Define elasticity.
A thin rod of length $$ \ell$$ and mass m is suspended horizontally by two vertical strings, A & B, one attached at each end of the rod. The density of the rod is given by $$\rho (x)=$$$${{\rho _ 0}(x/\ell )^ 3}$$ where x = 0 corresponds to the position of string A. Give your answer in terms of m, $$\ell $$ and g.
The Hooke's law defines
A bar made of material whose Young's modulus is equal to $$E$$ and Poisson's ratio to $$\mu$$ is subjected to the hydrostatic pressure $$p$$.