Chapter 6, Problem 6.46P

150 kJ of work is done in a rigid container while the internal energy increases by 95 kJ. Find the heat transfer, in kJ.

A cycle HE does 60kJ of work per cycle. If the efficiency of the heat engine is 60%. The heat rejected per cycle is.

Air at 200kPa, 30°C is contained in a cylinder behind a piston with initial volume of 0.1 m3. The inside pressure balance ambient pressure of 100 kPa plus an external imposed force that proportional to V05, Now heat is transfer to the system to final pressure of 225 kPa. Find the work done for this process. (8.65 kJ)

A computer lab filled with 20 computers and 15 students is cooled by an air conditioningunit on a day where it is 90 oF outside. The room temperature is 72 oF. Assume an averagestudent generate 90 W of heat and each computer generates 150 W of heat. If the COP ofthe air conditioner is 2.5, what power input is required, in kW? If the air conditioneroperated at its maximum coefficient of performance, what power input would be required?

of air at 300 K and 150 kPa. It's now heated in a two- Q: A piston cylinder contains 1.5 step processes: first by a constant volume process to 1000 K second a constant pressure process to 1500 K. find the heat transfer for this processes.

A device, including a heat engine and a heatpump, will be designed to deliver energy to a Heat Source asshown in Fig.Q3. It takes waste energy at 75°C as a sourceQw1 to the heat engine rejecting heat at 30°C. The remainderQw2 goes into the heat pump that delivers a QH at 235°C. Ifthe total waste energy is 3 MW find the rate of energydelivered at the high temperature, QH.

A solar collector absorbed 40W/m2 heat from the atmosphere. This is equal to the convection brought by air for drying purpose. If the temperature of the air is 40C while the solar collector area's temperature is 80C and neglecting effect of radiation, find the convective heat transfer coefficient.

A water cooler for drinking water should cool 25 L/h water from 18 C to 10 C while the water reservoirs also gains 60 W from heat transfer. Assume that a small refrigeration unit with a COP of 2.5 does the cooling. Find the power input to the unit.

In a turbine, steam enters with an enthalpy of 1275 Btu/lb, and leaves with an enthalpy of 1115 Btu/lbm. The transferred heat is 13 Btu/ibm. Find the turbine work in hp where the steam flow rate is 5 lbm/sec?