1- The rear window of an automobile is defogged by passing warm air over its inner surface with (k = 1.4 W/m- K.). If the warm air is at (T∞,i=40 °C) and the corresponding convection coefficient is (hi=30 W/m² .K), what are the inner and outer surface temperatures of (4 mm) thick window glass, if the outside ambient air temperature is (T∞,0=-10 °C) and the associated convection coefficient is (ho=65 W/m².K)?

1- The rear window of an automobile is defogged by passing warm air over its inner surface with (k = 1.4 W/m- K.). If the warm air is at (T∞,i=40 °C) and the corresponding convection coefficient is (hi=30 W/m² .K), what are the inner and outer surface temperatures of (4 mm) thick window glass, if the outside ambient air temperature is (T∞,0=-10 °C) and the associated convection coefficient is (ho=65 W/m².K)?

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

Q2) A short fin is attached to a flat surface temperature T = 40 °C. Determine the fin temperature at 5 cm from the base and the rate of heat loss from the entire fin. Considering that the ambient air temperature Too = 20 °C, convection coefficient h = 50 w/m².°C, fin conduction coefficient k = 300 W/m.°C, fin dimensions (L = 7cm, W = 5cm, t = 2mm), Perimeter, P = 10 cm. 612223 T=40 °C X = 5 cm L = 7 cm h=50 Too=20 k-300 W = 5 cm = 2mm
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.
You are designing a new eco-friendly thermal coffee mug. It is shaped like a small globe to minimize surface area, which is only about 0.04m^2. You use two 0.003m layers of recyclable PETE which has a thermal conductivity, k, of 0.2W/mK around a 0.01m layer of dead air, with a thermal conductivity of 0.026W/mK. Since this is for hot coffee, use a temperature difference of 40K. Q = Ax (T2-T1) / (R1 + R2 + etc) R =x/k. What is the heat lose through the surface in watts?
Example: Steam in a heating system flows through tubes whose outer diameter isD1=3 cm and whose walls are maintained at: = 1.5 cm 2= 3 cm temperature of 120°C. Circular aluminun fins ( k=180 W/m °C) of outer diamete D2 6 cm and constant thickness t =2 mn T r32 mm are attached to the tube, as shown in Fig The space between the fins is 3 mm, an thus there are 200 fins per meter lengtl of the tube. Heat is transferred to th surrounding air at T= 25°C, with a combined heat transfer coefficient of h= 60 W/m2 °C. Determine the increase in heat transfer from the tube per meter of its length as a result of adding fins. S 3 mm
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.
A cylindrical shape body of length is 1.9 m and diameter is 400 mm is inside a room where the ambient temperature is equal to 300 K. The initial temperature of the body is equal to 350 K. If the heat convective coefficient is equal to 1.3 W/m^2.K. What is the thermal conductivity K.
1- Microwave radiation is incident on one side of a planar wall with a heat conductivity coefficient k. (x=0) -D°b=(x)b leads to volumetric heating. While this surface is 9(W/m²) microwave radiation is fixed. kept at a constant temperature To, the other surface at x=L is very well insulated. Determine the temperature distribution T(x) in terms of x, L, k, qo and To.
A spherical ball with a diameter of 5 cm is suspended in the middle of a room with a temperature of 20°C. The temperature of the ball is 70°C. The heat transfer coefficient of the ball is 15 W/(m2.°C) and the emissivity of the ball surface is 0.8.What is the total heat transfer rate from the ball to the air assuming both temperatures are constant? Heat conduction through the suspension system can be neglected.
A plane wall of an oven with an insulation coating is attached to an insulated wall. The thermal conductivity and thickness of the insulation coating are 0.1 W/(m K) and 1 mm, respectively. The material of the plane wall is stainless steel 304. The density, thermal conductivity, and specific heat capacity of the stainless steel 304 are 7900 kg/m³, 74.9 W/(mK), and 477 J/(kg-K), respectively. The wall thickness of the stainless steel 304 is 15 mm. The temperature of the plane wall with the insulated coating is initially maintained at 30 °C. Suddenly, hot gas with a temperature of 1000 °C enters the oven. The convection heat transfer coefficient at the insulation coating surface is 70 W/(m²-K). Insulation Coating Stainless Steel 304 Oven Gas Perfectly Insulated Wall 1 X L 3-1) What is the overall heat transfer coefficient per unit area from the gas to the surface of the stainless steel? The answer should be given in the unit of W/(m²-K). 3-2) What is the value of the Biot number? 3-3)…
The rear window of an automobile is defogged by passing warm air over its inner surface. If the warm air is at Ti = 40°C and the = 30 W/m2-K, what are the inner and outer surface temperatures, in °C, of 4-mm-thick corresponding convection coefficient is h; window glass, if the outside ambient air temperature is To = -15°C and the associated convection coefficient is h, = 65 W/m²-K? o,0 Evaluate the properties of the glass at 300 K. Tsi i °C Ts,0 i °C
A car's rear window is defogged by the passage of hot air over its inner surface. If the hot air is at T∞, i = 40 °C and the corresponding convection heat transfer coefficient is hi = 30 W/(m²K), what are the temperatures of the inner and outer surfaces of the glass, which has 4 mm thick, if the outdoor ambient air temperature for T∞, e = −10 °C and the associated convective coefficient for he = 65 W/(m²K)?
1. Consider a 5-m-high, 8-m-long, and 0.22-m-thick wall whose representative cross section is as given in the Fig. The thermal conductivities of various materials used, in W/m-°C, are k = kr = 2, KB = 8,kc=20, KD = 15, and k = 35. The left and right surfaces of the wall are maintained at uniform temperatures of 300 °C and 100 °C, respectively. Assuming heat transfer through the wall to be one-dimensional, determine: (a) the rate of heat transfer through the wall; (b) the temperature at the point where the sections B, D, and E meet; and (c) the temperature drop across the section F. Disregard any contact resistances at the interfaces. 300°C 1 cm C A 4 cm B 4 cm 4 cm D C 6 cm 5 cm 6 cm E| F 10 cm 6 cm 100°C 8 m