Two kilograms of air within a piston-cylinder assembly execute a carnot power cycle with maximum and minimum temperatures of 750 k and 300 k respectively. the heat transfer to the air during the isothermal expansion os 60 kj. at the end of the isothermal expansion, the pressure is 600 kpa and the volume is 0.4 m^3. assuming the ideal gas model for the air determine: (a) the thermal efficiency(b) the pressure and the volume at the beginning of the isothermal expansion, in kpa and m^3 respectively(c) the work and heat transfer for each of the four processes in kj(d) sketch the cycle on a p-v coordinates

Line joining liquid phase with liquid and solid phase mixture is known as: a) liquidus b) solidus c) tie line d) none of the mentioned

For a gate width of 2 m into the paper, determine the force required to hold the gate abc at its location.

To save energy, the air supply to a 2000 ft office has been shut off overnight and the room temperature has dropped to 40°f. in the morning, the thermostat is reset to 70°f and warm air at 120 f begins to flov in at 200ft'/min. the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct. the air pressure is nearly 1 atm everywhere. ignoring heat transfer with the surroundings and kinetic and potential energy effects, estimate how long it takes for the room temperature to reach 70°f. plot the room temperature as a function of time.