Your answer is incorrect. Try again. A soda lime glass sphere of diameter D₁ = 25 mm. encased in a bakelite spherical shell of thickness L= 10 mm. The composite sphere is initially at a uniform temperature, T = 47°C, and is exposed to a fluid at T = 10°C with h = 30 W/m². K. Determine the center temperature of the glass at /= 150 sec. Neglect the thermal contact resistance at the interface between the two materials. The center temperature is 52.84

Your answer is incorrect. Try again. A soda lime glass sphere of diameter D₁ = 25 mm. encased in a bakelite spherical shell of thickness L= 10 mm. The composite sphere is initially at a uniform temperature, T = 47°C, and is exposed to a fluid at T = 10°C with h = 30 W/m². K. Determine the center temperature of the glass at /= 150 sec. Neglect the thermal contact resistance at the interface between the two materials. The center temperature is 52.84

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

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
Find the steady-state temperature distribution in a (very long) solid cylinder if the boundary temperatures are T(s=0, θ, z)=0 and T(s, θ, z=0)=s*sinθ
Below is a diagram of a pipe with 5 m radius, temperature of 5000 K, and k = 450 W/m-K. The pipe is covered by a steel that is 1.8 m thick with k = 17 W/m-K. The temperature inside is 5000 K while the temperature outside is 800 K. TB = 800 K TA = 5000 K k = 450 W/m-K K = 15 W/m-K Answer the following: 1. Calculate the system's heat loss per unit length (W/m²). 2. Calculate the temperature between the pipe and the steel (temperature in K). 5 m 1.8 m/
Question 5: Z=62 a. An iron sphere of mass (Z + 300)g is kept in a container having boiling water (100 °C). If the temperature of the sphere is 25.5°C, how much heat energy is absorbed by the iron sphere? Consider the specific heat of iron as 452J/kg. b. The wall of an industrial furnace is constructed from (Z + 3) cm thick fireclay brick having a thermal conductivity of 1.7 W/mK. Measurements made during steady-state operation reveal temperatures of 530°C and 375°C at the inner and outer surfaces, respectively. Find the rate of heat loss through a wall which is (Z + 5) cm by (Z + 3) m on a side.
A thin bar of length L = 3 meters is situated along the x axis so that one end is at x = 0 and the other end is at x = 3. The thermal diffusivity of the bar is k = 0.4. The bar's initial temperature f(x) = 300 degrees Celsius. The ends of the bar (x = 0 and x = 3) are then put in an icy bath and kept at a constant O degrees C. Let u(x, t) be the temperature in the bar at x at timet, with t measured in seconds. Find u(x, t) and then u7 (2, 0.1). Put uz (2, 0.1) calculated accurately to the nearest thousandth (3 decimal places) in the answer box.
A machine element as seen in the figure is made of pure copper. It has an inner diameter of D;=2.9 cm, outer diameter of Do=5.9 cm, and height of H=19 cm. The initial temperature of the element is 749 K, and then suddenly placed in an environment which has a temperature of Too=300O K. The temperature of the element is measured as 489 K, 4.8 minutes after the cooling process. If the lumped system method is applicable, determine the heat transfer coefficient of the environment, in W/(m²K). Note: All the surfaces should be considered to calculate the surface area. Not: Yüzey alanı hesaplamak için tüm yüzeyler dikkate alınmalıdır. Properties of pure copper: k=370 W/(mK), C=920 J/(kg°C), p=8933 kg/m³ H Dị
How long should it take to boil an egg? Model the egg as a sphere with radius of 2.3 cm that has properties similar to water with a density of = 1000 kg/m3 and thermal conductivity of k = 0.606 Watts/(mC) and specific heat of c = 4182 J/(kg C). Suppose that an egg is fully cooked when the temperature at the center reaches 70 C. Initially the egg is taken out of the fridge at 4 C and placed in the boiling water at 100 C. Since the egg shell is very thin assume that it quickly reaches a temperature of 100 C. The protein in the egg effectively immobilizes the water so the heat conduction is purely conduction (no convection). Plot the temperature of the egg over time and use the data tooltip in MATLAB to make your conclusion on the time it takes to cook the egg in minutes.
Problem 3: Refer to the rectangular region in the figure below, the inner boundary surfaces are insulated and heat genrated within the cast iron solid ġ" (kw/m'). Determine the temperature distribution within the salid where the boundary surfaces are kept at 20 C. where is the location of the maximum temperature? how much it will be if a =2b = 20 cm and c = 2d = 10 cm and heat gencration is 1 kW/m?? 2b 2d ZInsulation 20 ġ" (kW/m) 2a
A certain material has a thickness of 30 cm and a thermal conductivity of 0.04 W/m- °C. At a particular instant in time, the temperature distribution with x, the distance from the left face, is T = 150x ^ 2 - 30x , where x is in meters. Calculate the heat-flow rates atx x = 0 and x = 30 cm . Is the solid heating up or cooling down?
A thin bar of length L = 3 meters is situated along the x axis so that one end is at x = 0 and the other end is at x = 3. The thermal diffusivity of the bar is k = 0.4. The bar's initial temperature f(x) = 50 degrees Celsius. The ends of the bar (x = 0 and x = 3) are then put in an icy bath and kept at a constant 0 degrees C. Let u(x, t) be the temperature in the bar at x at time t, with t measured in seconds. Find u(x, t) and then u4 (2, 0.1). Put u4(2, 0.1) calculated accurately to the nearest thousandth (3 decimal places) in the answer box.
A chip that is of length L = 5.5 mm on a side and thickness t = 2.0 mm is encased in a ceramic substrate, and its exposed surface is convectively cooled by a dielectric liquid for which h = 150 W/m² K and To = 20°C. . Th Chip, q, T₁, P, Cp The time is Substrate In the off-mode the chip is in thermal equilibrium with the coolant (T; = T). When the chip is energized, however, its temperature increases until a new steady state is established. For purposes of analysis, the energized chip is characterized by uniform volumetric heating with a = 9 x 106 W/m³. Assuming an infinite contact resistance between the chip and substrate and negligible conduction resistance within the chip, determine the steady-state chip temperature Tƒ. Following activation of the chip, how long does it take to come within 1°C of this temperature? The chip density and specific heat are p = 2000 kg/m³ and c = 700 J/kg-K, respectively. The steady-state chip temperature Tf is i S. °C.
Conduction 1. A thermodynamic analysis of a proposed Brayton cycle gas turbine yields P= 5 MW of net power production. The compressor, at an average temperature of T. = 400°C, is driven by the turbine at an average temperature of T₁ = 1000°C by way of an L = 1m-long, d= 70mm - diameter shaft of thermal conductivity k = 40 W/m K. Compressor min T Combustion chamber Shaft L Turbine Th out (a) Compare the steady-state conduction rate through the shaft connecting the hot turbine to the warm compressor to the net power predicted by the thermodynamics- based analysis. (b) A research team proposes to scale down the gas turbine of part (a), keeping all dimensions in the same proportions. The team assumes that the same hot and cold temperatures exist as in part (a) and that the net power output of the gas turbine is proportional to the overall volume of the device. Plot the ratio of the conduction through the shaft to the net power output of the turbine over the range 0.005 m s Ls 1 m. Is a…