To cool a summer house without using a vapor compression refrigeration cycle, hot air is directed through a pipe and is submerged in the closest lake. The pipe is made of plastic with k = 0.15 W/mK with volumetric flow rate of 0.02 m3/s and inlet air temperature of 32˚C. If the water temperature is kept at 15˚C with a convection coefficient of 1000 W/m2K at the outer surface of the pipe, calculate the length that is needed to provide a discharge temperature of 22˚C (in meters)?

Two flowing streams of argon gas are adiabatically mixed to form a single flow/stream. one stream is 1.5 kg/s at 400 kpa and 200 c while the second stream is 2kg/s at 500 kpa and 100 ? . it is stated that the exit state of the mixed single flow of argon gas is 150 c and 300 kpa. assuming there is no work output or input during the mixing process, does this process violate either the first or the second law or both? explain and state all your assumptions.

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

Inadequate stores control is not an obstacle to effective work order system. (clo4) a)-true b)-false