Question 2a) Give the Stefan Boltzman equation and define each term.[4]b) A electric room heater (radiator) element is 25 cm long and 4 cm in diameter. The element dissipates heat to the surroundings at 1500 W mainly by radiation, the surrounding temperature being 15°C. Determine the equilibrium temperature of the element surface.[4]c) A composite cylinder consists of 10 cm radius steel pipe of 25 mm thickness over which two layers of insulation 30 mm and 35 mm are laid. The conductivities are 25 W/mK, 0.25 W/mK and 0.65 W/mK. The inside is exposed to convection at 300°C with h 65 W/m2K.The outside is exposed to air at 30°C with h 15 W/m2K. Determinei. the heat loss/m,the interface temperatures.ii. The overall heat transfer coefficient.[4][4][2]

2. A brass ring of diameter 10.00 cm at 20.0°C is heated and slipped over an aluminum rod of diameter 10.01 cm at 20.0°C. Assuming the average coefficients of linear expansion are constant, a. to what temperature must the combination be cooled to separate the two metals? b. What if the aluminum rod were 10.02 cm in diameter? (- 179°C, - 374°C]

3.4 Estimate the rate of heat loss due to radiation from a covered pot of water at 95 ° C. How does this compare with the 60 W that is lost due only to convection and conduction losses? What amount of energy input would be needed to maintain the water at its boiling point for 30 minutes? The polished stainless steel pot is cylindrical, 20 cm in diameter and 14 cm high, with a tight-fitting flat cover. The air temperature in the kitchen is about 25 ° C. State any assumptions you make in deriving your estimates

A chamber for heat curing large aluminum sheets lacquered black on both sides operates by passing the sheets vertically between two steel plates 150 mm apart. One of the plates is at 300°C, and the other exposed to the atmosphere, is at 25°C. i) What is the temperature of the lacquered sheet? and ii) What is the heat transferred between the wall when equilibrium has been reached? Neglect the convection effects and the emissivity of lacquered sheet is 1.

Hello, I am a mechanical engineering student and want to upload this question as I have an exam in early June about thermodynamics. I have been given a question that will help me answer my exams in June. Please could you answer showing step by step guidance on how to answer this question with the formula clearly shown.    Thank you very much

Four infinite, parallel, black, opaque plates transfer heat by radiation as shown in figure 1.19. Find T2 and T3 [T2= 75.53°C]. This is a heat transfer problem from the textbook A Heat Transfer Textbook fifth edition

c) What is the temperature of the iron heating element at x=30mm (in ∘C)? Use the origin defined in the given diagram. d) At which position x (in mm) does the iron heating element experience its highest temperature? e) In this scenario outlined in this question (constant heat generation under steady-state, 1-D conditions), can the temperature distribution in the iron ever be linear? Yes or No? Justify your reasoning.

need help with part D

A container holds a sample of ideal gas in thermal equilibrium, as shown in the figure. (Figure 1) One end of the container is sealed with a piston whose head is perfectly free to move, unless it is locked in place. The walls of the container readily allow the transfer of energy via heat, unless the piston is insulated from its surroundings. Refer to the pV diagram presented to answer the questions below. (Figure 2) In each case, the piston head is initially unlocked and the gas is in equilibrium at the pressure and volume indicated by point 0 on the diagram. Starting from equilibrium at point 0, what point on the pV diagram will describe the ideal gas after the following process? "Lock the piston head in place, and hold the container above a very hot flame."

You are working with a derivative of naphthalene and, like its parent compound, it has a high triple point and sublimates fairly readily at temperatures near room temperature. At temperatures below 400 K, you find that the vapor pressure of its solid can be represented by the function P 4200 K (1)-11.5 = 11.5 1 atm T Use this equation to estimate the normal sublimation temperature of this compound, Tsubl (in K).