A steel rod has a radius of `10 mm` and a length of `1.0 m.A` `100 kN` force stretches it along its length. Calculate the elongation of the steel rod. [Young's modulus of steel is `2.0×10^11N/m^2`]

Modulus of elasticity of a material is the ratio of stress and strain. One end of a rope of length 4.5 m and diameter 6 mm is fixed to the branch of a tree.A monkey weighing 100 N jumps to catch the free end and stays there.Find the elongation of the rope.(Young's modulus= 4.8×10^11 N/m^2 ).