A cable used to lift heavy materials like steel I-beams must be strong enough to resist breaking even under a load of 2.1 x 106 Newton. For safety, the cable must support twice that load.
(a) Obtain what cross-sectional area should the cable have if it's to be made of steel?
(b) Obtain by how much will a 7.0 meter length of this cable stretch when subject to the 2.1 x 106 N load?