Q9.25Multiple choice
- (a)A steel wire of mass µ per unit length with a circular cross section has a radius of 0.1 cm. The wire is of length 10 m when measured lying horizontal, and hangs from a hook on the wall. A mass of 25 kg is hung from the free end of the wire. Assuming the wire to be uniform and lateral strains << longitudinal strains, find the extension in the length of the wire. The density of steel is 7860 kg m–3 (Young’s modules Y=2×1011 Nm–2).
- (b)If the yield strength of steel is 2.5×108 Nm–2, what is the maximum weight that can be hung at the lower end of the wire? Mechanical Properties of Solids