Consider two cylindrical rods that are identical in size and shape, but are made of different materials. The rods are placed between two walls that are maintained at different temperatures. The direction of heat conduction is from the warmer wall (left) to the cooler wall (right). k1 k1 = 205 W /(m-K) TC k2 = 109 W/(m-K) (1) Tw %3D k2 A = A2 = A k1 k2 Tw Tc (II) d d

Consider two cylindrical rods that are identical in size and shape, but are made of different materials. The rods are placed between two walls that are maintained at different temperatures. The direction of heat conduction is from the warmer wall (left) to the cooler wall (right). k1 k1 = 205 W /(m-K) TC k2 = 109 W/(m-K) (1) Tw %3D k2 A = A2 = A k1 k2 Tw Tc (II) d d

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter16: Temperature And The Kinetic Theory Of Gases

Section: Chapter Questions

Problem 33P: At 25.0 m below the surface of the sea, where the temperature is 5.00C, a diver exhales an air...

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One easy way to reduce heating (and cooling) costs is to add extra insulation in the attic of a house. Suppose a single-story cubical house already had 15 cm of fiberglass insulation in the attic and in all the exterior surfaces. If you added an extra 8.0 cm of fiberglass to the attic, by what percentage would the heating cost of the house drop? Take the house to have dimensions 10 m by 15 m by 3.0 m. Ignore air infiltration and heat loss through windows and doors, and assume that the interior is uniformly at one temperature and the exterior is uniformly at another.
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An astronaut performing an extra-vehicular activity (space walk) shaded from the Sun is wearing a spacesuit that can be approximated as perfectly white ( e=0 ) except for a 5 cm × 8 cm patch in the form of the astronaut's national flag. The patch has emissivity 0.300. The spacesuit under the patch is 0.500 cm thick, with a thermal conductivity k 0.0600 W/m , and its inner surface is at a temperature of 20.0 . What is the temperature of the patch, and what is the rate of heat loss through it? Assume the patch is so thin that its outer surface is at the same temperature as the outer surface of the spacesuit under it. Also assume the temperature of outer space is 0 K. You will get an equation that is very hand to solve in closed form, so can solve it numerically with a graphing calculator, with software, or even by trial and error with a calculator.
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