The cylinder cd of the assembly is heated from t1 = 30°c to t2 = 180°c using electrical resistance. also, the two end rods ab and ef are heated from t1 = 30°c to t2 = 50°c. at the lower temperature t1 the gap between c and the rigid bar is 0.7 mm. determine the force in rods ab and ef caused by the increase in temperature. rods ab and ef are made of steel, and each has a cross-sectional area of 125 mm^2. cd is made of aluminum and has a crosssectional area of 375 mm^2. est = 200 gpa, eal = 70 gpa, ast = 12(10^-6)1/°c, and aal = 23(10^-6)1/°c.