During which process would heat be transferred from a fire to a metal container that it is in direct contact with the fire? a. conduction b. convection c. radiation

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?

23) A carpenter is driving a 15.0-g steel nail into a board. His 1.00-kg hammer is moving at 8.50 m/s when it strikes the nail. Half of the kinetic energy of the hammer is transformed into heat in the nail and does not flow out of the nail. What is the increase in temperature of the nail after the three blows that the carpenter needs to drive the nail in completely? The specific heat of steel is 448 J/kg. K. A) 2.7 K B) 7.7 K C) 3.6 K D) 1.8 K E) 8.1 K

10.) Specific heat capacity is related to the amount of internal energy a. Needed to change the temperature of one gram of a substance by one degrees C. b. Transferred by one molecule. c. Transferred by one object d. A specific object has.