A slice of pie and a slice of cake are at room temperature. You put both in the refrigerator to cool them down. Later you check and you notice that the pie is a colder temperature than the cake. Does the pie or the cake have higher conductivity? Explain. (Both the cake and pie are the same shape and mass)

Assume Lake Michigan contains 4.90 x 1012 m³ of water, and assume the water's density is that of water at 20°C and 1 atm. (a) How much energy (in J) is required to raise the temperature of that volume of water from 12.2°C to 24.4°C? 4.1E19 From the density of water and the volume, what is the mass of the water? What is specific heat? How is it related to the energy input, mass, and temperature change? Use it to solve for the energy. Be careful with units. J (b) How many years would it take to supply this amount of energy by using a power of 1,400 MW generated by an electric power plant? 926 How is power related to energy and time? Knowing the energy from part (a), can you find the time? Be careful with units. Make sure you convert the time in seconds to years. yr

A small metal cube with a thermal mass mc and an initial temperature 0 is dropped into a container of water that is actively maintained at a constant temperature 0w. The cube quickly comes to rest on the bottom surface of the container. The bottom surface is maintained at a constant temperature 0 (note that this is different from 0w). The thermal resistance between the cube and the water is Rcw while the thermal resistance between the bottom surface of the container and the cube is RCB. The temperature of the cube is denoted by 0c. a) Draw the system schematic indicating the assumed directions of the heat transfer rates. Label all the nodes and system parameters. b) Derive the governing equation for the temperature of the cube, 0c. c) Where does to appear in the system schematic and how does it affect the governing equations? d) Calculate the steady-state temperature of the cube, css, assuming the following system parameters: 0o = 21°C, 0B = 6°C, 0w = 0°C, Rcw = 2°C/W, and RCB = 4°C/W

Equal masses of substance A at 98.1°C and substance B at 26.2°C are placed in a well-insulated container of negligible mass and allowed to come to equilibrium. If the equilibrium temperature is 77.4°C, which substance has the larger specific heat? a) substance A     b) The answer depends on the exact initial temperatures. c) More information is required. d) The specific heats are identical.