Air flows in a steady flow in a pipeline whose internal diameter is constant. at a particular section of the pipe the pressure, temperature and velocity are 250 psia, 700° r and 35 ft/sec, respectively. the specific volume corresponding to these conditions is 1.28 ft/lbm. at a section farther downstream the pressure is 400 psia, the velocity is 55 ft/sec and the temperature is 1700° r. a. determine the specific volume of the air at the downstream section. b. what is the magnitude and direction of the heat transfer in btu per pound?

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

Aturning operation is performed with following conditions: rake angle of 12°, a feed of 0.35 mm/rev, and a depth of cut of 1.1 mm. the work piece is aluminum alloy 6061 with t6 heat treatment (a16061-t6). the resultant chip thickness was measured to be 1.0 mm. estimate the cutting force, fc. use shear stress of 207 mpa and coefficient of friction on the tool face of 0.6.

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 the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct.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.