Thermal conductivity k (9%) Problem 10: Suppose a house's walls are 13 cm thick and and have an average thermal conductivity twice that of glass wool. Substance (J/s•m C) Glass wool Wool 0.042 0.04 Glass 0.84 Human body Ceramic Wood Air Fatty tissue 0.2 0.84 0.08-0.16 0.023 0.2 Styrofoam 0.010 ©theexpertta.com 50% Part (a) Calculate the rate of heat conduction, in watts, through the house's walls. Assume there are no windows or doors. The surface area of the walls is 140 m² and their inside surface is at 18.5°C, while their outside surface is at 5.15°C. Grade Summary Q'At = Deductions 0% 100% Potential sin() cos() tan() 9 HOME Submissions Attempts remaining: 10 (0% per attempt) detailed view cotan() asin() acos() E 4 5 atan() acotan() sinh() cosh() tanh() cotanh() END ODegrees O Radians VO BACKSPACE DEL CLEAR Submit Hint Feedback I give up! Hints: 0% deduction per hint. Hints remaining:1 Feedback: 0% deduction per feedback. 50% Part (b) How many 1.00-kW room heaters would be needed to balance the heat transfer due to conduction? Round your answer to the nearest integer value. 63 2. 1.

Thermal conductivity k (9%) Problem 10: Suppose a house's walls are 13 cm thick and and have an average thermal conductivity twice that of glass wool. Substance (J/s•m C) Glass wool Wool 0.042 0.04 Glass 0.84 Human body Ceramic Wood Air Fatty tissue 0.2 0.84 0.08-0.16 0.023 0.2 Styrofoam 0.010 ©theexpertta.com 50% Part (a) Calculate the rate of heat conduction, in watts, through the house's walls. Assume there are no windows or doors. The surface area of the walls is 140 m² and their inside surface is at 18.5°C, while their outside surface is at 5.15°C. Grade Summary Q'At = Deductions 0% 100% Potential sin() cos() tan() 9 HOME Submissions Attempts remaining: 10 (0% per attempt) detailed view cotan() asin() acos() E 4 5 atan() acotan() sinh() cosh() tanh() cotanh() END ODegrees O Radians VO BACKSPACE DEL CLEAR Submit Hint Feedback I give up! Hints: 0% deduction per hint. Hints remaining:1 Feedback: 0% deduction per feedback. 50% Part (b) How many 1.00-kW room heaters would be needed to balance the heat transfer due to conduction? Round your answer to the nearest integer value. 63 2. 1.

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter11: Energy In Thermal Processes

Section: Chapter Questions

Problem 75AP: An aluminum rod and an iron rod are joined end to end in good thermal contact. The two rods have...

See similar textbooks

Similar questions

What mass of water at 25.0C must be allowed to conic to thermal equilibrium with a 1.85-kg cube of aluminum initially at 1.50 102C to lower the temperature of the aluminum to 65.0C? Assume any water turned to steam subsequently recondenses.
Stars A and B have the same temperature, but star A has twice the radius of star B. (a) What is the ratio of star As power output to star Bs output due to electromagnetic radiation? The emissivity of both stars can be assumed to be 1. (b) Repeat the question if the stars have the same radius, but star A has twice the absolute temperature of star B. (c) Whats the ratio if star A has both twice the radius and twice the absolute temperature of star B?
Suppose a person is covered head to foot by wool clothing with average thickness of 2.00 cm and is transferring energy by conduction through the clothing at the rate of 50.0 W. What is the temperature difference across the clothing, given the surface area is 1.40 m2?
A steam pipe is covered with 1.50-cm-thick insulating material of thermal conductivity 0.200 cal/cm C s. How much energy is lost every second when the steam is at 200.C and the surrounding air is at 20.0C? The pipe has a circumference of 800. cm and a length of 50.0 m. Neglect losses through the ends of the pipe.
Stars A and B have the same temperature, but star A has twice the radius of star B. (a) What is the ratio of star As power output to star Bs output due to electromagnetic radiation? The emissivity of both stars can be assumed to be 1. (b) Repeat the question if the stars have the same radius, but star A has twice the absolute temperature of star B. (c) Whats the ratio if star A has both twice the radius and twice the absolute temperature of star B?
The concrete sections of a certain superhighway are designed to have a length of 25.0 m. The sections are poured and cured at 10.0C. What minimum spacing should the engineer leave between the sections to eliminate buckling if the concrete is to reach a temperature of 50.0C?
An aluminum rod and an iron rod are joined end to end in good thermal contact. The two rods have equal lengths and radii. The free end of the aluminum rod is maintained at a temperature of 100.C, and the free end of the iron rod is maintained at 0C. (a) Determine the temperature of the interface between the two rods. (b) If each rod is 15 cm long and each has a cross-sectional area of 5.0 cm2, what quantity of energy is conducted across the combination in 30. min?
Suppose a person is covered head to foot by wool clothing with average thickness of 2.00 cm and is transferring energy by conduction through the clothing at the rate of 50.0 W. What is the temperature difference across the clothing, given the surface area is 1.40m2 ?
An aluminum rod and an iron rod are joined end to end in good thermal contact. The two rods have equal lengths and radii. The free end of the aluminum rod is maintained at a temperature of 100.C, and the free end of the iron rod is maintained at 0C. (a) Determine the temperature of the interface between the two rods. (b) If each rod is 15 cm long and each has a cross-sectional area of 5.0 cm2, what quantity of energy is conducted across the combination in 30. min?
The height of the Washington Monument is measured to be 170 m on a day when the temperature is 35.0C. What will its height be on a day when the temperature falls to 10.0C ? Although the monument is made of limestone, assume that its thermal coefficient of expansion is the same as marble's.
The thermal conductivities of human tissues vary greatly. Fat and skin have conductivities of about 0.20 W/m K and 0.020 W/m K, respectively, while other tissues inside the body have conductivities of about 0.50 W/m K. Assume that between the core region of the body and the skin sin face lies a skin layer of 1.0 mm, fat layer of 0.50 cm, and 3.2 cm of other tissues. (a) Find the R-factor for each of these layers, and the equivalent R-factor for all layers taken together, retaining two digits. (b) Find the rate of energy loss when the core temperature is 37C and the exterior temperature is 0C. Assume that both a protective layer of clothing and an insulating layer of unmoving air a absent, and a body area of 2.0 m2.
Suppose that the average velocity (vrms) of carbon dioxide molecules (molecular mass is equal to 44.0g/mol ) in a ?ame is found to be 1.05105m/s. What temperature does this represent?