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A plane wall, 7.5 cm thick, generates heat internally at the rate of w/m^3. One side of the wall is insulated, and the other side is exposed to an environment at 90 degrees celsius.
Assuming negligible internal resistance, derive a differential equation that could be solved to determine the rod temperature as a function of time during the heating process.
The R-410a is compressed to 2MPa, 60 C in a reversible (internally) polytropic process. Find the polytropic exponent n ans calculate the work and heat transfer.
Determine the instantaneous rate of heat transfer from a 1.5-cm-diameter ball bearing with a surface temperature of 150 C submerged in an oil bath at 75 C if the surface convective heat transfer co
Refrigerant 134a at 700 kPa and 40oC is expanded adiabatically in a closed system to 60 kPa. Determine the work produced, in kJ/kg, and final enthalpy for an isentropic expansion efficiency of 80 pe
A 30-cm-diameter, 5-m-long steam pipe passes through a room where the air temperature is 20 C. If the exposed surface of the pipe is a uniform 40 C, find the rate of heat loss from the pipe to the
A dynamics student is called on to investigate a two-car collision. It's known that car A struck car B. Mass of car A is 2000 kg and mass of car B is 1200 kg. Both Car A and B then skidded 8 meters.
What mass of waste brine is expelled in one day? What is the ratio of the mass of fresh water produced to the mass of water in the incoming brine?
The potential for air pollution by particulate matter (PM2.5 and/or PM10) is best assessed by constructing the terminal velocity vs. particle size diagram.
The final pressure in cylinder reaches 200 kPa after the heating process, find the temperature of the contents in the cylinder at the end of the process.
The emission of an air pollutant is often influenced more by reaction kinetics than by chemical equilibrium. Verify whether this is true for a hypothetical case of hydrocarbon (methane) combustion.
The final pressure is 1.4 MPa. Determine the work and the heat transfer for the process (both in kJ/kg), assuming ideal gas behavior.
A mechanical engineer who recently graduated with a master's degree is contemplating starting his own commercial heating and cooling company. He can purchase a Web Page design package aimed at deliv
Determine the equilibrium mole fractions of NO and NO2. Comment on their change with respect to the exhaust gas composition at 2000 K.
Blocks D and F weigh 50 lb each and block E weighs 80 lb. Determine the length s for equilibrium. Neglect the size of the pulleys.
A Carnot heat engine receives heat from a reservoir at 900C at a rate of 800 kJ/min and rejects the waste heat to the ambient air at 27C.
Compute the unit cell edge length for a 95 wt% Pt-5 wt% Cu alloy. Assume that densities of Cu and Pt are 8.94 and 21.45 g/cm3 and atomic weight are 63.55 and 195.08 g/mol, respectively.
Find the rate of fuel (kW) being burned just to drive the air conditioner and its COP. Find the flow rate of cold air the air conditioner can provide.
Fe transforms from a BCC to FCC crystal structure at around 911 degrees C. FCC Fe has an atomic radius .129 nm. What is the percent volume change following the transformation?
Power generated by the turbing exactly equals this power required by the compressor. Find the enthalpy per unit mass at the exit of the engine.
Estimate the annual emissions of CO2 and SO2 from a 1500 MW(th) steam generation plant if the boiler operates at 1800 K and 2 atm with 15% excess air. The coal used has 75% C, 5% H, 1.5% N, 2.5% S,
Calculate the power required to drive a steady-flow compressor if air flowing at a rate of 1kg/s enters at 100kPa, Temp=20C with a velocity od 60m/s and leaves at 240kPa.
What is the minimum flow rate of water required to scrub out 90.0% of the incoming NH3? L/hr. What is the mole fraction of NH3 in the scrubbed waste gas stream? mol NH3/mol waste gas.
A flue passing hot exhaust gases has a square cross section, 300mm to a side. The walls are constructed of refractory brick 150mm thick with a thermal conductivity of 0.85 W/m*K.
A gas within a piston-cylinder assembly undergoes a thermodynamic cylce consisting of three processes. process 1-2: compression with pV=constant, from p1=1bar , V1= 2m^3, V2= 0.2m^3, U2-U1=100kJ, pr