1. The upper surface of a 50-cm-thick solid brass plate (k-109 W/m K) is being cooled by water with temperature of 10°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 190°C, respectively. Determine the water convection heat transfer coefficient and the water temperature gradient at the upper plate surface. Water T₁,2

1. The upper surface of a 50-cm-thick solid brass plate (k-109 W/m K) is being cooled by water with temperature of 10°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 190°C, respectively. Determine the water convection heat transfer coefficient and the water temperature gradient at the upper plate surface. Water T₁,2

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

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The upper surface of a 50-cm-thick solid brass plate (k=109 W/mK) is being cooled by water with temperature of 10°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 190°C, respectively. Determine the water convection heat transfer coefficient and the water temperature gradient at the upper plate surface. Water Ts.l · Ts.,2
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Consider a 1.2-m-high and 2-m-wide double-panewindow consisting of two 3-mm-thick layers of glass (k =0.78 W/m·K) separated by a 3-cm-wide air space. Determinethe steady rate of heat transfer through this window and thetemperature of its inner surface for a day during which theroom is maintained at 20°C while the temperature of the outdoorsis 0°C. Take the heat transfer coefficients on the innerand outer surfaces of the window to be h1 = 10 W/m2·K andh2 = 25 W/m2·K and disregard any heat transfer by radiation.Evaluate air properties at a film temperature of 10°C and1 atm pressure. Is this a good assumption?
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The upper surface of a 50-cm-thick solid brass plate (k-109 W/mK) is being cooled by water with temperature of 10°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 190°C, respectively. Determine the water convection heat transfer coefficient and the water temperature gradient at the upper plate surface. Water Ts.1 Ts.2
(b) A transistor with a height of 0.4 cm and a diameter of 0.6 cm is mounted on a circuit board as shown in Figure 3. The transistor is cooled by air flowing over it with an average heat transfer coefficient of 30 W/m².K. If the air temperature is 55°C and the transistor case temperature is not to exceed 70°C, determine the amount of power this transistor can dissipate safely. Disregard any heat transfer from the transistor base. Air 55°C Power transistor 0.6 cm T, ≤ 70°C -0.4 c 0.4 cm- Figure 3
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A person is found dead at 5PM in a room whose temperature is 20°C. Thetemperature of the body is measured to be 25°C when found, Modeling thebody as a 30-cm-diameter, 1.70-m-long cylinder and the heat transfer coefficient estimated to be 8 W/m2·K. and using the lumped system analysis as a rough approximation, estimate the time of death of the person.
A 0.2-m-long and 25-mm-thick vertical plate (k = 15 W/m-K) separates the hot water from the cold water. The plate surface exposed to the hot water has a temperature of 100°C, and the temperature of the cold water is 7°C. Determine the temperature of the plate surface exposed to the cold water (Ts c). Start the iteration process with an initial guess of 53.5°C for the Tsc- Plate Cold water 7°C Hot water 100°C Given: The properties of water at Tfr = 30.25°C. k = 0.6033 W/m-K, p = 995.5 kg/m3, u = 0.0007935 kg/m s, B = 0.0003072 K-1 The thermal conductivity of the plate is given as kplate = 15 W/m-K.