A copper rod of Lc, cross-sectional area Ac, and modulus of elasticity Ec is inserted into an aluminum tube as shown below. The aluminum tube has a cross-sectional area of Aa, modulus of elasticity Ea, and length La. Assume that the deformations of both tube and rod are elastic. a) Find the deformations of aluminum tube and copper road due to the axial load P, which is large enough to close the small gap Delta? (20%) b) Find the axial strain if no gap exists between the aluminum tube and copper road? (10%) Lc La P = 100 kN La = 205 mm Le = 210 mm FIXED END A' Rigid end-plate Copper rod Aluminum tube Aa = 20 mm Ac = 22 mm O Section A-A' Ea 70 GPa Ec- 120 GPa