a) A house walls that are 14 cm thick and have an averagethermal conductivity four times that of glass wool. Assumethere are no windows or doors. The walls' surface area is1200000 cm2 and their inside surface is at 19°C, while theiroutside surface is at 5°C. (Thermal conductivity of glass wool0.042 W/m°C)(i) Calculate the rate of heat conduction through housewalls?(ii) How many 150W room heaters would be needed tobalance the heat transfer due to conduction? (approximatenumber)

Given, Thickness of wall d = 14 cm = 0.14 m Surface area of wall A = 1200000 cm2 = 120 m2…

Answered: a) A house walls that are 14 cm thick…

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

See similar textbooks

Similar questions

a) A house walls that are 16 cm thick and have an average thermal conductivity three times that of cork. Assume there are no windows or doors. The walls' surface area is 1450000 cm² and their inside surface is at 18 °C, while their outside surface is at 4°C. (Thermal conductivity of cork is 0.042 W/m°C) (1) Calculate the rate of heat conduction through house walls? (ii) How many 200oW room heaters would be needed to balance the heat transfer due to conduction? (approximate number) b) A spherical infrared heater of radius 6.2 cm has an emissivity of 0.71. What temperature must it run at if the required power is 0.5 kW? Neglect the temperature of the environment. (Stefan's constant = 5.67*10-8 Wm- 2K-4) The temperature of the heater in Celsius =
3. (a) The rate of heat transfer through a wood shingles roof of 4.50 m length, 3.90 m width and in 8.50 cm thickness is 126.65 W. The temperature of outside and inside-surface is 33.5 °C and 26.5 °C, respectively. (i) Determine thermal resistance, R of the wood shingles roof. (ii) Calculate the thermal conductivity. Give your answer in 3 decimal places. (iii) If a glass wool with higher thermal resistance is used to replace the wood shingles roof, determine which material tend to have lesser rate of heat transfer.
One of the windows in a house has the shape of a square 1.0 m on a side. The glass in the window is 0.50 cm thick, andhas a coefficient of thermal conductivity of k = 0.84 W>1m # K2. (a) How much heat is lost through this window in oneday if the temperature difference between the inside and outside of the window is 21 C°? (b) Suppose all the dimensionsof the window—height, width, and thickness—are doubled. If everything else remains the same, by what factor doesthe heat flow change?
1) The walls of a house are 11 cm thick and have an average thermal conductivity two times that of cork. The walls' surface area is 850000 cm2 and their inside surface is at 18°C, while their outside surface is at 4°C. (Thermal conductivity of cork is 0.036 W/m°C). Calculate, (i) The rate of heat conduction through house walls in Watts: (1) Amount of heat conducted in Joules, in 5 min: 2) A spherical infrared heater of radius 6.5 cm and an emissivity of 0.82 radiates 0.48 kW of power. Given, Stefan's constant = 5.67x10 Wm K Calculate, Temperature of the heater in Celsius: 1) A 275-turns square loop of 34 cm on a side, carrying a current of 22 A creates a torque of 385 N m when the plane of the coil makes an angle 38° with the magnetic field.
A homeowner is unhappy with her heating costs. One wall of her house is 4 meters tall and 8 meters wide and has no windows, and it is made of brick and mortar with a thermal conductivity of 1.0 W m K . It is 40 cm thick. The house is heated to a temperature of 20 ◦C inside. (a) What is the rate of heat loss through the wall on a day when it is 0◦C outside? (b) A layer of rock mineral wool, which has a thermal conductivity of 0.032 W m K is to be installed on the interior surface of the brick wall. How thick should the layer be to lower the rate of heat transfer through this wall to half its original value? (c) If the rock mineral wool is instead installed on the outer surface, is the thickness required the same?
Steam flowing at a rate of 10,000 kg/h and at 120°C is condensed using cooling water at an average temperature of 20°C. The condenser contains 800 tubes which have an outer diameter of 18 mm. Estimate the heat transfer coefficient (a) if the condenser is vertical and (b) if the condenser is horizontal with tubes 3 m long and condensation takes place outside the tubes.
(a) Calculate the rate of heat conduction (in W) through house walls that are 11.5 cm thick and that have an average thermal conductivity twice that of glass wool. Assume there are no windows or doors. The surface area of the walls is 150 m2 and their inside surface is at 20.0°C, while their outside surface is at 5.00°C. 1565.21 (b) How many 1 kW room heaters would be needed to balance the heat transfer due to conduction? (Round your answer to the next whole integer.) 2 1 kW room heaters
1) The walls of a house are 24 cm thick and have an average thermal conductivity four times that of glass wool. The walls' surface area is 800000 cm? and their inside surface is at 21°C, while their outside surface is at 5°C. (Thermal conductivity of glass wool is 0.042 W/m°C). Calculate, (i) The rate of heat conduction through house walls: (ii) Amount of heat in Joules, conducted in 5 min: 2) A spherical infrared heater of radius 6.3 cm and an emissivity of 0.79 radiates 0.48 kW of power. Given, Stefan's constant = 5.67x108 Wm¯ 2K4. Calculate, Temperature of the heater in Celsius:
a) A house walls that are 20 cm thick and have an average thermal conductivity four times that of glass wool. Assume there are no windows or doors. The walls' surface area is 1000000 cm² and their inside surface is at 23° Çwhile their outside surface is at 4° C (Thermal conductivity of glass wool is 0.042 W/m°C) (i) Calculate the rate of heat conduction through house walls? (ii) How many 150W room heaters would be needed to balance the heat transfer due to conduction? (approximate number) b) A spherical infrared heater of radius 6.05 cm has an emissivity of 0.74. What temperature must it run at if the required power is 0.42 kW? Neglect the temperature of the environment. (Stefan's constant = 5.67*10-8 Wm¯-2K-4) The temperature of the heater in Celsius =
(a) Calculate the rate of heat conduction through house walls that are 13.0 cm thick and that have an average thermal conductivity twice that of glass wool. Assume there are no windows or doors. The surface area of the walls is 120m^2 and their inside surface is at 18.0ºC, while their outside surface is at 5.00ºC. (b) How many 1-kW room heaters would be needed to balance the heat transfer due to conduction?
Suppose you stand with one foot on ceramic (k=33 W/mK) flooring and one foot on a wool carpet (k =0.033 W/mK), making contact over an area of 65cm2 with each foot. Both the ceramic and the carpet are 1 cm thick and are 7ºC on their bottom sides. If the top of the ceramic and carpet at 32ºC, calculate the following: a) the rate of heat transfer that occur from the foot kept on wool carpet in watts b) the rate of heat transfer that occur from the foot kept on ceramic in watts

Recommended textbooks for you

College Physics

Physics

ISBN:

9781305952300

Author:

Raymond A. Serway, Chris Vuille

Publisher:

Cengage Learning

University Physics (14th Edition)

Physics

ISBN:

9780133969290

Author:

Hugh D. Young, Roger A. Freedman

Publisher:

PEARSON

Introduction To Quantum Mechanics

Physics

ISBN:

9781107189638

Author:

Griffiths, David J., Schroeter, Darrell F.

Publisher:

Cambridge University Press

College Physics

Physics

ISBN:

9781305952300

Author:

Raymond A. Serway, Chris Vuille

Publisher:

Cengage Learning

University Physics (14th Edition)

Physics

ISBN:

9780133969290

Author:

Hugh D. Young, Roger A. Freedman

Publisher:

PEARSON

Introduction To Quantum Mechanics

Physics

ISBN:

9781107189638

Author:

Griffiths, David J., Schroeter, Darrell F.

Publisher:

Cambridge University Press

Physics for Scientists and Engineers

Physics

ISBN:

9781337553278

Author:

Raymond A. Serway, John W. Jewett

Publisher:

Cengage Learning

Lecture- Tutorials for Introductory Astronomy

Physics

ISBN:

9780321820464

Author:

Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden

Publisher:

Addison-Wesley

College Physics: A Strategic Approach (4th Editio…

Physics

ISBN:

9780134609034

Author:

Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field

Publisher:

PEARSON

SEE MORE TEXTBOOKS