9.47. Considera wire of 1.5-m length and 2-mm diameter. It is clamped at the upper end and a 5-kg mass hangs at the lower end. Young's modulus is 9 x 1010 N/m, and its Poissoti's ratio is 0.25. Calcu, late (a) the extension of the wire, (b) the decrease in the cross-sectional area due to the lateral strain (c) the work done by the stretching force, and (d) the potential etiergy of the stretched wire. 9.48. Calculate the work done per unit volume in the following cases: (a) a shearing stress shearing the body through an angle 6, and (b) uniform stress P producing a volume strain V.