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A stirring rod transfers energy by work until the pressure is 2 bar. The air behaves as an ideal gas. Determine the work, in kJ, and the amount of entropy produced, in kJ/K. Comment.
For each process of a closed system, show the initial and final states on a properly-labeled T-s diagram, evaluate the change in entropy, and apply the entropy balance and energy balances.
Is it economical to increase the carburizing temperature to 1000C? Justify your answer. The activation energy for difussion of C in Fe is 32,900 cal/mole and R is 1.987 cal/mol.K.
Calculate the critical heat flux on a large horizontal surface for the following fluids at 1 atm: mercury, ethanol, and refrigerant R-134a. Compare these results to the critical heat flux for water
Determine: The maximum theoretical power that can be developed by the turbine, in MW, and the corresponding turbine exit temperature.
A cup of coffee (12oz) 0.0125 ft^3 that is at 140 degrees F sits on a desk. Calculate. The amount of heat transfer from the coffee, in Btu. The entropy produced during the process, But/degrees R.
Stray heat transfer and kinetic and potential energy effects are negligible. Determine (a) the isentropic turbine efficiency and (b) the rate of entropy production within the turbine, in KW/K.
Hydrogen at 25 bar, 450°C enters an adiabatic turbine and expands to 2 bar, 160°C with a mass flow rate of 0.2 kg/s. Determine the power produced and the isentropic efficiency.
Determine (a) the temperature of the refrigerant exiting the compressor, in °C (b) the power input to the compressor, kW and (c) the rate of entropy production kW/K.
Saturated liquid water is heated at constant pressure in a steady-flow device until it is a saturated vapor. Calculate the heat transfer, in kJ/kg, when the vaporization is done at a pressure of 80
It strikes the smooth ground at a distance of 20 ft away and bounces upward at 30 degrees. Determine the initial velocity, final velocity, and coefficient of restitution between the ball and the gro
When r = 17ft , the car is moving on a horizontal circular path with a speed of 32ft/s . If the boom is shortened at a rate of 3ft/s , determine the speed of the car when r = 10ft.
The building is estimated to be losing heat at a rate of 118,572 kJ/h when the outside temperature drops to 4.2oC. Determine the minimum power required (kW) to drive the heat pump unit for this outs
Steam at 1 bar enters an adiabatic heat exchanger with a quality of 0.896 and exits as a saturated liquid. Determine the volumetric flow rate (m3/s) of the steam entering the heat exchanger.
The temperature on the inner face is 25 degrees celcius, and the temperature on the outer face os 0 degrees celcius. How much heat per day is lost through the wall?
If the electric motor driving the pump has an efficiency of 85% and the cost of electricity is $0.10 per kW hour, find annual cost of electricity powering the system.
Air enters an adiabatic diffuser at 320 K and 100 kPa with a velocity of 642.9 m/s. At the diffuser exit, the temperature is 520 K. Determine the velocity (m/s) at the exit of the diffuser.
Saturated water vapor at 13.32 bar enters an insulated throttling valve which drops the pressure to 1.50 bar. Determine the temperature (oC) of the steam at the exit of the valve.
The average speed of blood leaving the left ventricle is 120 cm/s. Determine the difference in height between these two locations.
Determine the torque exerted on the 10mm long (high) inner cylinder. (The blood is filled to the top of the inner cylinder).
What can be concluded about Ixy if in addition to the first condition both moments of inertia are also equal to each other in another system of coordinates that is rotated by 45 degrees with respect
Determine the power needed to drive the pump if the pump isentropic efficiency is 87%. Also determine the outlet temperature of the water.
Determine the absolute pressure of the water at the ground level. Atmospheric pressure is 101.325 kPa. Acceleration due to gravity is 9.81 m/s2.
The gap between the two plates is h = 0.005 m. The fluid has a viscosity of 2 N-s/m2. Assume the fluid is Newtonian. Calculate the shear stress acting on the top and bottom surfaces (at y = 0 and y =
Hydrogen at 25 bar, 450°C enters an adiabatic turbine and expands to 2 bar, 160°C with a mass flow rate of 0.2 kg/s.