Consider a rod transmitting a tensile force. The following materials are being considered for the given application: tungsten carbide, zinc alloy, polycarbonate polymer, and aluminum alloy. 3. a. Determine the material index fM). b. Using Ashby chart (Fig. 2.19), select the best material for its strength to weight ratio.

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.