91Ó°ÊÓ

What is the theoretical maximum efficiency of an engine operating between \(100^{\circ} \mathrm{C}\) and \(500^{\circ} \mathrm{C}\) ?

A heat engine operating between \(473 \mathrm{~K}\) and \(373 \mathrm{~K}\) runs at about \(70 \%\) of its theoretical maximum efficiency. What is its efficiency?

An engine operates between \(10^{\circ} \mathrm{C}\) and \(200^{\circ} \mathrm{C}\). At the very best, how much heat should we be prepared to supply in order to output \(1000 \mathrm{~J}\) of work?

A furnace supplies \(28 \mathrm{~kW}\) of thermal power at \(300^{\circ} \mathrm{C}\) to an engine and exhausts waste energy at \(20^{\circ} \mathrm{C}\). At the very best, how much work could we expect to get out of the system per second? SSM

A kitchen refrigerator extracts \(75 \mathrm{~kJ}\) of energy from a cool chamber while exhausting \(100 \mathrm{~kJ}\) per second to the room. What is its coefficient of performance?

W is the coefficient of performance of a Carnot refrigerator operating between \(0^{\circ} \mathrm{C}\) and \(80^{\circ} \mathrm{C}\) ?

An electric refrigerator removes \(13.0 \mathrm{MJ}\) of heat from its interior for each kilowatt-hour of electric energy used. What is its coefficient of performance?

A certain refrigerator requires \(35 \mathrm{~J}\) of work to remove \(190 \mathrm{~J}\) of heat from its interior. (a) What is its coefficient of performance? (b) How much heat is ejected to the surroundings at \(22^{\circ} \mathrm{C}\) ? (c) If the refrigerator cycle is reversible, what is the temperature inside the refrigerator? SSM

A refrigerator is rated at \(370 \mathrm{~W}\). Its interior is at \(0^{\circ} \mathrm{C}\) and its surroundings are at \(20^{\circ} \mathrm{C}\). If the second law efficiency of its cycle is \(66 \%\), how much heat can it remove from its interior in \(1 \mathrm{~min}\) ?

Heat is added to \(1 \mathrm{~mol}\) of air at constant pressure, resulting in a temperature increase of \(100^{\circ} \mathrm{C}\). If the same amount of heat is instead added at constant volume, what is the temperature increase? The molar specific heat ratio \(\gamma=C_{P} / C_{V}\) for the air is \(1.4\).