A furnace wall consists of 2 ft of brick . The brick has a thermal conductivity of 0.6 Btu/ hr sq ft ( ° F /ft), a specific heat of 0.2 Btu/ lb ° F, and a density of 110 lb/cu ft. The temperature at the inside surface of the wall is 1100 ° F , and at the outside surface, 200 ° F . (a) Calculate the thermal diffusivity of the brick . (b) Calculate the heat loss per hour through a wall 10 ft high and 10 ft long (c ) Calculate

Please help me with these questions An element on a hot stove is maintained at a constant temperature of Thot = 105 °C and a pan is placed on the element. The base of the pan can be taken to be a uniform circular layer of diameter 15 cm and thickness 7.0 mm, and with a thermal conductivity of 15 W m-1 K-1. a. The air above the pan comes into thermal equilibrium with the element. Write down the temperatures on the top and bottom surfaces of the pan and the rate of heat flow through the pan. Use the zeroth law of thermodynamics to explain your answer. A fan is then switched on so that the air above the pan is maintained at Tcold = 20 °C, and the system reaches a steady state. b. Identify the heat transfer mechanism that is being used to maintain the air at Tcold. c. Calculate the rate of heat transfer through the pan. A 3.0 mm thick layer of soup is added to the pan and the system again reaches a steady state. The temperature at the boundary between the pan and the soup is 95 °C.  d.…

A house, for cooling purposes, consists of two zones: the attic area zone A and the living area zone B (see below figure). The living area is cooled by a 2-ton air conditioning unit that removes 19 °F per thousand Btu. The time constant for heat 4 41,000 Btu/hr. The heat capacity of zone B is transfer between zone A and the outside is 2 hr, between zone B and the outside is 4 hr, and between the two zones is 4 hr. If the outside temperature stays at 90°F, how warm does it eventually get in the attic zone A? It eventually gets to be F in the attic zone A. (Type an integer or decimal rounded to the nearest hundredth as needed.) 4 hr Î A 쉽 4 hr B 2 hr 41,000 Btu/hr

Question 1: In your own words, write down the differences between thermodynamic and heat transfer. (3 Marks) Question 2: Estimate the heat loss per square metre of surface through a brick wall 0.5 m thick when the inner surface is at 400 K and the outside surface is at 300 K. The thermal conductivity of the brick may be taken as 0.7 W/mK. (2 Marks) Question 3: A furnace is constructed with 0.20 m of firebrick, 0.10 m of insulating brick, and 0.20 m of building brick. The inside temperature is 1200 K and the outside temperature is 330 K. If the thermal conductivities are as shown in the figure below, estimate the heat loss per unit area. (5 Marks) 1200 K 330 K Fire brick X=0.20 m Insulating brick x=0.10 m Ordinary brick X=0.20 m k = 1.4 k = 0.21 k = 0.7 (WimK)