The pin-connected structure consists of a rigid bar ABCD and two axial members. Bar (1) is steel [E = 215 GPa, 10.9 × 10−6/°C ] with a cross-sectional area of A1 = 480 mm2. Bar (2) is an aluminum alloy [E = 50 GPa, 22.1 × 10−6/°C] with a cross-sectional area of A2 = 280 mm2. The bars are unstressed when the structure is assembled. Assume L=830 mm, a= 290 mm, b=560 mm, c=650 mm, and P=33 kN. After a concentrated load of P = 33 kN is applied and the temperature is decreased by 59°C, determine: (a) the normal stresses , in bars (1) and (2). (b) the vertical deflection vD of the rigid bar at D (positive if down, negative if up).