TRUE OR FALSE. Why? 1. Heat flows SPONTANEOUSLY from hot objects to cold objects and vice versa, as exhibited by heat pumps.

7. How much thermal energy do you need to raise 1.0 kg of water at room temperature 35 °C to boiling? The specific heat of water is 4190 J/kg-K. * A. 136 kilojoules B. 272 kilojoules C. 54 kilojoules D. 1416 kilojoules O E. 4190 kilojoules

4) A ground source heat pump heats a building by extracting heat from the ground and pumping it into the building. Define: Qc = heat extracted from the ground, Qn= heat pumped into the building, W = electric energy used by the heat pump, Tc= temperature of the ground, T = temperature of building (Qc, Qn, and W are positive by definition). Assume Tr > Tc. a) Draw a diagram showing energy flow in and out of the heat pump. b) Write a general expression for the change AS in the entropy of the "universe", that is the heat pump plus the cold and hot reservoirs, in terms of the quantities defined above. Now assume ideal (reversible) operation, and take Te= 10 °C and Tp= 20 °C. What is the coefficient of performance (ČOP) of the heat pump? By what factor would this change if we had Tc = 0 °C instead?

#1. What are the three mechanisms for heat transfer and how do they differ?