1.Calculate the required area of an air to air heat exchange to cool 20,000 cfm from 1200 F to 400 F. Assume ambient air at 80 F will be heated to 800 F by the exchange. Assume heat losses are 10 % and that the overall heat transfer coefficient is 1.0 Btu/hr-ft^2- °F
2.The bar DA is rigid and is originally held in the horizontal position when the weight W is supported from C. If the weight causes B to be displaced downward 0.025 in., determine the strain in wires DE and BC. Assume that the wires BC and DE have an area of 0.002 in2, and
E = 29,000 ksi.