A britle material has the properties Sut = 30 kpsi and Suc = 90 kpsi. Using the coulomb mohr and modified mohr theories , Determine the factor or safety for the following states of plane stresses. a) σx = 25 kpsi σy =15 kpsib) σx = 15 kpsi σy = - 15 kpsic) σx = 20kpsi τxy= -10 kpsid) σx = - 15 kpsi σy =10 kpsi τxy= -15 kpsie) σx = - 20 kpsi σy =- 20 kpsi τxy= -15 kpsi

For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater