Consider an idealized two-cell cross-section shown below in Figure Q3. Ignore the contribution of skin to the direct loads and moments of area (that is assume skin thickness to be zero for calculating geometric properties). Shear modulus = 10 kPa and skin thickness = 5cm everywhere, and the boom areas are given in the Table below. 1m 2m i Bi (m) 1m 6 5 Figure Q3. An idealized two-cell cross-section 1 3 4 5 2 0.2 0.2 0.2 0.1 6 0.2 0.1 (a) Calculate the second moments of area of the cross-section about its centroidal axes. [4] (b) A bending moment My = 100 N-m is applied about its centroidal axes. Calculate the maximum tensile and compressive direct stresses acting on the section. [3] (c) A shear force Sy needs to be applied. Find the location through which the shear force should be applied so that there is no twist in the cross-section. [8] (d) If a torque T = 100 N-m is applied, calculate the resulting twist rate. [5]