Consider a 4m diameter spherical tank initially filled with liquid nitrogen at 1 atm and -196°C (density is 810 kg/m^3 at those conditions). The tank is exposed to 20°C ambient air with a heat transfer coefficient of 25 W/m^2°C. The temperature of the thin shelled-spherical tank is observed to be almost the same as the temperature of the nitrogen inside. Disregarding any radiation heat exchange, determine the rate of evaporation of the liquid nitrogen in the tank because of the heat transfer from the ambient air (heat of vaporization is 198 kJ/kg).

Amass of 1.5 kg of air at 120 kpa and 24°c is contained in a gas-tight, frictionless piston-cylinder device. the air is now compressed to a final pressure of 720 kpa. during the process, heat is transferred from the air such that the temperature inside the cylinder remains constant. calculate the boundary work input during this process.

Apump is used to circulate hot water in a home heating system. water enters the well-insulated pump operating at steady state at a rate of 0.42 gal/min. the inlet pressure and temperature are 14.7 lbf/in.2, and 180°f, respectively; at the exit the pressure is 60 lbf/in.2 the pump requires 1/15 hp of power input. water can be modeled as an incompressible substance with constant density of 60.58 lb/ft3 and constant specific heat of 1 btu/lb or. neglecting kinetic and potential energy effects, determine the temperature change, in °r, as the water flows through the pump.

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false