In an electrically heated home, the temperature of the ground in contact with a concrete basement wall is 11.9 °C. The temperature at the inside surface of the wall is 19.6 °C. The wall is 0.17 m thick and has an area of 6.9 m². Assume that one kilowatt hour of electrical energy costs $0.10. How many hours are required for one dollar's worth of energy to be conducted through the wall? Number i Units

A 39% maximum efficient coal-fired power plant needs to produce 600 MW of power.  A. To achieve maximum efficiency, if the waste water is dumped into a 13 degree Celsius lake, what temperature must the steam be heated to?  B. Since coal contains 27 kJ of energy per gram, how many kg of coal must be burned in a day?

The amount of heat per second conducted from the blood capillaries beneath the skin to the surface is 210 J/s. The energy is transferred a distance of 1.7 x 10-3 m through a body whose surface area is 1.6 m². Assuming that the thermal conductivity is that of body fat, determine the temperature difference between the capillaries and the surface of the skin. Number i Units

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