Agas is contained in a vertical piston–cylinder assembly by a piston with a face area of 60 in2 and weight of 100 lbf. the atmosphere exerts a pressure of 14.7 lbf/in2 on top of the piston. a paddle wheel transfers 3 btu of energy to the gas during a process in which the elevation of the piston increases slowly by 1 ft. the piston and cylinder are poor thermal conductors, and friction between the piston and cylinder can be neglected. determine the change in internal energy of the gas, in btu.

Ahot wire operates at a temperature of 200°c while the air temperature is 20°c. the hot wire element is a tungsten wire of 5 um diameter and 2 mm in length. plot using excel current, heat transfer and heat generated by the wire for air velocity varying from 1-10 m/s in steps of lm/s? matlab the sensor voltage output, resistance, or assume nu 0.989 re033pr13 take air properties at tr (200°c20°c)/2 = 110°c properties of tungsten: c 0.13 kj/kg.k 3 p 19250 kg/m k (thermal conductivity) = 174 w/m.k