Agas is contained in a vertical piston–cylinder assembly by a piston with a face area of 60 in2 and weight of 100 lbf. the atmosphere exerts a pressure of 14.7 lbf/in2 on top of the piston. a paddle wheel transfers 3 btu of energy to the gas during a process in which the elevation of the piston increases slowly by 1 ft. the piston and cylinder are poor thermal conductors, and friction between the piston and cylinder can be neglected. determine the change in internal energy of the gas, in btu.

To design a steam turbine to produce 12,000 hp power. a engineer comsiders using a steady state stean low st 1160fr and engineer considers using a steady state steam flow at 1160°r and 450 psia to drive this steam turbine. the exhaust of the steam is cooled by the lake (vacuum). heat losing to the surroundings is measured at a rate of 555.55 btu/s. (a) sketch the system with the given conditions. (b) neglecting kinetic and potential energy changes from inlet to exit, determine the volumetric flow rate of the steam at the inlet, (ft'/hr). must clearly show unit conversions at crtical terms.