A uniform steel plate has an area of 0.839 m². When subjected to a temperature difference between its sides, a heat current (the amount of heat that flows per unit time) of 32500 W is found to flow through it. What is the temperature gradient? What is the temperature difference when the plate is 0.0453 m thick? The thermal conductivity of steel is 50.2 W/ (m · K).

A classroom has dimensions 8.00 m x 10.00 m x 3.00 m. A 1000 W electric space heater is being used to warm the room from 5.00°C to 20.00°C on a cold morning. If the density of air is 1.29 kg/m°, and the specific heat capacity of air is 1004 J/(kg-K), how long will it take to heat the room? Assume no loss of thermal energy to the surroundings. A) 1.30 minutes B) 241 minutes C) 45.3 minutes O D) 77.7 minutes

The thermal conductivities of human tissues vary greatly. Fat and skin have conductivities of about 0.20 W/m · K and 0.020 W/m · K respectively, while other tissues inside the body have conductivities of about 0.50 W/m · K. Assume that between the core region of the body and the skin surface lies a skin layer of 1.0 mm, fat layer of 0.50 cm, and 3.2 cm of other tissues. (a) Find the R-factor for each of these layers, and the equivalent R-factor for all layers taken together, retaining two digits. Rskin      m2 · K/W Rfat      m2 · K/W Rtissue      m2 · K/W R      m2 · K/W (b) Find the rate of energy loss when the core temperature is 37°C and the exterior temperature is 0°C. Assume that both a protective layer of clothing and an insulating layer of unmoving air are absent, and a body area of 2.0 m2. W

A glass coffee pot has a 9.00 cm diameter circular bottom in contact with a heating element that keeps the coffee warm with a continuous 50.0-W heat input. (a) What is the temperature of the bottom of the pot, if it is 2.90 mm thick and the inside temperature is 67.8°C? The thermal conductivity of the pot is 0.84 J/(s · m · °C). *Answer in °C, please

9. The rod below with the cross section surface area of 0.12 m² is laterally insulated. The rod has a thermal conduction constant of 100 W/m.°C. If the temperature along the rod changes according to the function T=ax²+b, develop a model to find the heat which is transferred through the rod? 1 X=0 T=70 °C Heat flow X=2m T=30 °C X