Answer Happy

1. Is it possible for the efficiency of a reversible heat engine to be greater than 1.0? Explain in one or two sentences. 2. Does adding heat to a system always increase its internal energy? Explain in one or two sentences. 3. When a gas expands isothermally, it does work. What is the source of energy needed to do this work? Explain in one or two sentences. 4. Does a gas do any work when it expands adiabatically? If so, what is the source of the energy needed to do this work? Explain in one or two sentences. 5. Give an example of a physical property that varies with temperature and describe how it is used to measure temperature. Explain in a few sentences.