Question

A rigid bar of mass 15 kg is supported symmetrically by three wires each 2 m long. The wires at each end are of copper and the middle one is of iron. Determine the ratio of their diameters if each has the same tension. Young's modulus of elasticity for copper and iron are 110 x 10⁹ N/m² and 190 x 10⁹ N/m² , respectively.

Answer 1

Each wire has same tension, so each wire will have same extension. Also as they have same length, each wire will have same strain