Aclosed, rigid tank fitted with a paddle wheel contains 2.0 kg of air, initially at 200oc, 1 bar. during an interval of 10 minutes, the paddle wheel transfers energy to the air at a rate of 1 kw. during this time interval, the air also receives energy by heat transfer at a rate of 0.5 kw. these are the only energy transfers. assume the ideal gas model for the air, and no overall changes in kinetic or potential energy. do not assume specific heats are constant. determine the change in specific internal energy for the air, in kj/kg, and the final temperature of the air, in oc.

When at a point two solid phase changes to one solid phase on cooling then it is known as a) eutectoid point b) eutectic point c) peritectic point d) peritectoid point

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Two technicians are discussing the intake air temperature (iat) sensor. technician a says that the computer uses the iat sensor as a backup to the engine coolant temperature (ect) sensor. technician b says that the powertrain control module (pcm) will subtract the calculated amount of fuel if the air measures hot. who is correct