A heat engine with a thermal efficiency of 40 percent rejects 1000 kJ/kg of heat. Determine the amount of heat it receives.

If a house needs a minimum heat transfer rate of 75 kJ/h (i.e., 75 kJ of heat needs to be transferred into the house during one hour) to maintain a pleasant indoor temperature. If one wants to use a heat pump with a COP of 5.55 to fulfill this heat transfer rate, what is the corresponding electricity (in kWh) consumption to run such a heat pump for one hour?

“Heat can never pass from a colder to warmer body without another concurrent change within.” What is the concurrent change (or work) done by the modern refrigerator allowing heat to flow to a warmer body?     1st law of thermodynamics     Expansion and cooling     Compression and heating of refrigerant     3rd law of thermodynamics     Expansion and heating

Please give the detailed solution. Mechanical -thermo