10. Aluminum-lithium (Al-Li) alloys have been developed by the aircraft industry to reduce the weight and improve the performance of this aircraft. A commercial aircraft skin material having a density of 2.47g/cm3 is desired. Compute the concentration of Li (wt%) that is required.

Carbon dioxide gas expands isotherm a turbine from 1 mpa, 500 k at 200 kpa. assuming the ideal gas model and neglecting the kinetic and potential energies, determine the change in entropy, heat transfer and work for each kilogram of co2.

An ideal otto cycle with air as the working fluid has a compression ratio of 8. the minimum and maximum temperatures in the cycle are 300 k and 1340 k. use constant specific heats at room temperature to determine (a) the amount of heat transferred to the air during the heat- addition kj/kg, (b) the thermal efficiency, and (c) the thermal efficiency of a carnot cycle ope limits. process, in rating between the same temperature

The proportional limit is always greater than the yield strength for a material. a)-trune b)- false