Apiston-cylinder device contains 0.15 kg of air ini- tially at 2 mpa and 350°c. the air is first expanded isothermally to 500 kpa, then compressed polytropically with a polytropic exponent of 1.2 to the initial pressure, and finally compressed at the constant pressure to the initial state. determine boundary work for each process and the net work of the cycle

On a average work day more than work place firs are reorted

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk

The flow rate of air through a through a pipe is 0.02 m5/s. a pitot static tube is placed in the flow. the radius of the pitot static tube is 1 mm. assuming the flow to be steady and the air to be at 300k, calculate the difference in total and static pressure if the diameter of the pipe is: (a) d 0.1 m d 0.05 m (c) d 0.01 m