A wood slab with a thickness of 0.05 m is subjected to a heat flux of 40 W/m4. The left and right surface temperatures of the wood slab are kept at çohstant temperatures of 56°C and 20°C, respectively. What is the thermal conductivity of the wood slab? Thermal conductivity: W/m.'C

This question requires the use of the conduction charts given in the appendix at the end of this paper. A wooden sphere of diameter 5 cm is initially at a uniform temperature of 21 °C. Its surface temperature is suddenly raised to 83 °C. The thermal conductivity and thermal diffusivity of the wood are 0.15 W/m K and 0.82 x 10-7 m2/s, respectively. a) Calculate the temperature 2 cm beneath the surface of the sphere 30 min after the sudden increase in temperature. b) Calculate the energy gained by the sphere during this time.

An uninsulated steam pipe passes through a room in which the air and walls are at 25°C. The outside diameter of the pipe is 88 mm, and its surface temperature and emissivity are 200°C and 0.80 respectively. If the coefficient associated with free convection heat transfer from the surface to the air is 15W/m2-k, what is the rate of heat loss for a 5 meter pipe?   Round your answer to 2 decimal places.

The thermal conductivities of human tissues vary greatly. “Fat” and “skin” have conductivities of approximately 0.200 W /m 0K and 0.0200 W /m 0K, respectively, while other “tissues” inside the body have conductivities of approximately 0.500 W /m 0 Assume that between the core region of the body and the skin surface lies a “skin” layer of 1.00mm, a “fat” layer of 0.500 cm., and 3.20 cm. layer of other “tissues”. A)Find the R-factor for each of these three layers, and the R-factor for all layers taken together

An industrial cold room has four 200 mm thick walls made of concrete. The walls are insulated on the outside with a layer of foam 60 mm thick. Cladding with a thickness of 15 mm protects the foam on the outside from the elements. The composite wall surface temperatures are –3 °C on the inside and 18 °C on the outside of the room respectively. The thermal conductivities of concrete, foam and cladding are 0.75, 0.35 and 0.5 W/m K respectively.   Assuming perfect thermal contact between the layers of the composite walls, draw the typical temperature distribution across the layers and determine the heat energy gained per hour through all 4 walls of the room with a total surface area of 20 m2. What does this heat energy represent in terms of the refrigeration system of the cold room?