The pressure, temperature, and Mach number at the entrance to a duct through which air is flowing are 250 kPa, 26°C, and 1.4, respectively. At some other point in the duct, the Mach number is found to be 2.5. Assuming isentropic flow, find the temperature, velocity, and pressure at the second section. Also, find the mass flow rate through the duct per square meter at the second section.

Plot schematically the tensile stress versus strain curves for a typical thermoplastic material at a temperature below its glass transition temperature (tg and at a temperature above its tg, respectively. do the same for a typical thermosetting material. list in a table any differences or similarities between the two materials at t> tg and t < tg, respectively, and relate them to the structures of the two types of polymers