A steel pad supporting heavy machinery rests on four short, hollow, cast iron piers. The ultimate strength (ou) of the cast iron in compression is 65 ksi and Young's modulus (E) is 10.0 x 10 ksi. The outer diameter of each pier is d= 6.0 in. and the wall thickness is t=0.40 in. Assume the weight of the machinery is evenly split over the four piers. (a) What is the longitudinal strain in each pier if the machinery weighs 450 kips (1 kip = 1000 pounds)? Provide the answer to thousandths of an inch: 0.0001 (b) Using a factor of safety of 1.3 with respect to ultimate strength and the same load in part (a), what is the smallest wall thickness of the pier (t) that is possible with the same outer diameter d? Provide you answer to hundredths of an inch: 0.01.