1) Define the following terms:a) Internal energyb) Specific heat

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.- In a laboratory experiment, a calorimeter is used to determine the specific heat of iron. 80 g of dry iron pellets are placed in the cup and heated to 95°C. The mass of the inner aluminum cup with a stirrer made of the same material is 60 g. The calorimeter is partially filled with 150 g of water at 18°C.The hot pellets quickly expired in the cup and the calorimeter was sealed, as shown in Figure 17.5. After the system has reached thermal equilibrium, the final temperature is 22°C. Calculate the specific heat of iron HEAT SPECIFIC Iron: 470 J/kgC: 0.113 cal/gCAluminum: 920 J/kgC: 0.22 cal/gC

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