Answer self assessment questions:
4-34: even though heat and work, are different forms of the same quality (energy), custom has
continued to express them using different units. name two customary units used to measure!
heat energy

In general, how do thermosetting plastics compare to thermoplastics in mechanical and physical properties?

When subject to a steady load (within elastic range) over a long period of time, what is the major difference in material behavoir between steel and plastic?

At steady state, air at 200 kpa, 325 k, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. the inlet cross-sectional area is 6 cm2. at the duct exit, the pressure of the air is 100 kpa and the velocity is 250 m/s. neglecting potential energy effects and modeling air as an 1.008 kj/kg k, determine ideal gas with constant cp = (a) the velocity of the air at the inlet, in m/s. (b) the temperature of the air at the exit, in k. (c) the exit cross-sectional area, in cm2