A brittle material has the properties Sut = 30 kpsi and Suc = 90 kpsi. Using the brittle Coulomb-Mohr and modified-Mohr theories, determine the factor of safety for the following states of plane stress. (a) σx = 25 kpsi, σy = 15 kpsi (b) σx = 15 kpsi, σy = –15 kpsi (c) σx = 20 kpsi, τxy = –10 kpsi (d) σx = –15 kpsi, σy = 10 kpsi, τxy = –15 kpsi (e) σx = –20 kpsi, σy = –20 kpsi, τxy = –15 kpsi

Acarnot refrigerator operates in a room in which the temperature is 21°c and of power when operating. if the food compartment of the refrigerator is consumes 3 kw to be maintained at 2°c, determine (a) the coefficient of performance of the cycle and (b) the rate of heat removal from the food compartment. refrigerator cycle that has a higher coefficient of performance than that of the discussed (e) is it possible to develop a carn ot refrigerator, operating between the same temperature limits? explain