Find the elastic deformation energy of a steel rod of mass m=3.1 kg stretched by a tensile strain `1.0xx10^-3`. (Density of steel `7.8xx10^3 kg//m^3`)

Calculate the maximum length of a vetica steel wire just before its snaps. Breaking stress of steel is 7.9 times 10^9 N.m^-2 and density of steel is 7.9 times 10^3 .m^-3 .

State Stokes' law. The terminal velocity of copper ball of radius 2.0 mm falling through a tank of oil at 20^@ C is 6.5 cm. s^-1 . Compute the coefficient of viscosity of the oil at 20^@ C . (Density of oil is 1.5xx10^3 kg.m^-3 , density of copper is 8.9xx10^3 kg. m^-3 )

Density of aluminium is 2700 kg/ m^(3) . Find the relative density of aluminium given that density of water =10^(3)kg//m^(3)