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Find the ideal thermal efficiency of the engine on the air-standard basis, if the exponent of the expansion and compression line is 1.35.
An ideal otto cycle has a compression ratio of 8:1. At the beginning of the compression process, air is at 95 kPa and 27 degree C, and 750 kj/kg of heat is transferred to air during the constant-vol
How much of this insulation must be added to reduce the heat transfer by 75 percent from that which would be experienced by the bare wire?
What is the speed of the rocket relative to the Earth once the rocket's mass is reduced to half its mass before ignition? What is the thrust on the rocket if it burns fuel at the rate of 56.5 kg/s?
A machine gun fires 174 g bullets at a speed of 610 m/s at a rate of 502 bullets/min. What steady force must be applied to the gun to hold it stationary?
What if the 820 kg car actually moves backwards with a speed of 1.9 m/s right after the collision instead of having a perfectly inelastic collision.
A 45.6-kg girl is standing on a 141-kg plank. Both originally at rest on a frozen lake that constitutes a frictionless, flat surface. What is the velocity of the plank relative to the ice surface?
Treat nitrogen as an ideal gas & determine the nitrogen's filial temperature, in degree C. Begin your analysis with the first law of thermodynamics. Find the final pressure, in kPa.
Show the process on T-v and P-v phase diagrams. Label the states and key pressure and temperature. Evaluate the work, in kJ. Evaluate the heat transfer, in kJ.
A well insulated, thin-walled, double-pipe, counter-flow heat exchanger is to be used to cool oil [Cp = 2.20 kJ/(kg C)] from 150 C to 40 C at a rate of 2 kg/s by water.
A well insulated, thin-walled, double-pipe, counter-flow heat exchanger is to be used to cool oil. Determine the rate of heat transfer in the heat exchanger and the exit temperature of water.
Determine (a) the electric power required (kW) to drive the pump if friction losses are neglected; and (b) the average velocity (m/s) of the water if a 20 cm diameter (ID) pipe is used.
Determine (a) the heat transfer from the compressor an (b) the volume flow rate of the refrigerant at the compressor inlet. Ignore changes in kinetic and potential energy for your calculation.
If the temperature and pressure of the steam at the nozzle exit at 400 degrees celcius and 2 MPa, the exit area of the nozzle is?
Account for variation of specific heats with temperature and model the engine as a dual cycle. Determine the amount of heat supplied per cylinder.
On an overflow structure of 50 degrees slope the water depth (measured normal to the surface of the structure) is 1.2 m (4 ft) and the streamlines are essentially straight and parallel.
What are the sources of error in your system? How can you minimize the experimental error? How would you modify this system to determine the specifi heat of a solid?
A hydraulic power generation (turbine-generator) plant is installed at a site 200 m below the free surface of a large water reservoir that can supply water at a rate of 3800 kg/s steadily.
Water is pumped from a lake to a storage tank 40 m above at a rate of 55 L/s, while consuming 22.6 kW of electric power to run the motor. Determine the overall efficiency of the motor-pump unit.
The cost of electricity is 10 cents per kWh. What is the yearly electricity cost of this refrigerator, assuming that it runs only half the time?
A 1 ton car is climbing a 200 m long uphill road with a slope of 30° from horizontal. What is the power required to get the work done in 15 seconds at a constant velocity?
The inlet area of the compressor is 130 CM^2. Assuming surrounding to be 25C find:the reversible power in kw and the entropy generation in kw and irreveribility in kw.
What is the specific gas constant for this gas in (j/kg-k), initial mass of the O2, final mass of O2, chang in total internal energy contained in the cylinder.
During a certain process the specific hea capacity of the system is given by cn=(0.4+0.004(T-273))kj/kg-k. temprature is measured in degress k.
If the specific heats cp=1000j/kgk and cv=772j/kgk what is the change in internal energy and enthalpy of the gas going from process 1 to process 2.