A stell wire is suspended vertically from a rigid support. When loaded with weight in air, it extends by `x_1.` When the weight is completely inside the water, the extension becomes `x_2.` Find the relative density of the meterial fo the weight ?

Explanation

Let V be the volume of the load attached to lower end of steel wire Young's modulus Y, area cross- section A and length of wire L. Let `rho` be the relative dentiy of rod. The, `Y = (FL)/(Ax_1) = (V rho g L)/(Ax_1) …. (i)`
When load is immersed in liquid, then `Y = ((V rho g - V xx 1 xx g)L)/(A x_2) ......(ii)`
`From (i) and (ii), (rho)/(x_1) = (rho -1)/(x_2) or rho x_2 = rho x_1 - x_1`
or `x_1 = rho(x_1 - x_2) or rho = (x_1)/(x_1 - x_2)`