Q1:A 1.5mx0.8m double glass window consists of two glass(k=0.78 W/mC) layers with a4 mm thickness for each layer, seperated by a 10 mm thick of still air gap. If the thermalcnductivity of still air is 0.026 W/mC, what is the rate of heat transfer through the window, ifthe temperatures of the inner and outer surfaces of the window are 15 and -8°C respectively.يتكون شباك ارتفاعه 0.8m وعرضه 1.5m من طبقتين من الز جـاج 0.78 k=( (°CW/m سمك كل واحدة منهما Am m ومفصولتين بطبقة هوائية سمكها 10mm .إذا كان معامل الانتقال بالتوصيل ل لهواء الساكن W/m °C 0.026 أحسب معدل انتقال الحرارة خلال الشباك إذا كانت درجة حرارة السطح الداخلي ل لشباك C° 15ودرجة حرارة السطح الخارجي C° 8-.T2T3هواءGlassAirGlassAx,A X,A X3

Given, Area, A=1.5 m×0.8 m=1.2 m2, Length of glass pane, L=4 mm=0.004 m, Length of air gap, L1=10…

A 1.5mx0.8m double glass window consists of two glass(k=0.78 W/mC) layers with a 4 mm thickness for each layer, seperated by a 10 mm thick of still air gap. If the thermal cnductivity of still air is 0.026 W/mC, what is the rate of heat transfer through the window, if the temperatures of the inner and outer surfaces of the window are 15 and -8°C respectively.

A 1.5mx0.8m double glass window consists of two glass(k=0.78 W/mC) layers with a 4 mm thickness for each layer, seperated by a 10 mm thick of still air gap. If the thermal cnductivity of still air is 0.026 W/mC, what is the rate of heat transfer through the window, if the temperatures of the inner and outer surfaces of the window are 15 and -8°C respectively.

University Physics Volume 2

18th Edition

ISBN:9781938168161

Author:OpenStax

Publisher:OpenStax

Chapter1: Temperature And Heat

Section: Chapter Questions

Problem 117AP: (a) Calculate the rate of heat conduction through a double-paned window that has a 150-m2 area and...

See similar textbooks

Similar questions

(a) What is the rate of heat conduction through the 3.00-cm-thick fur of a large animal having a I .40-m surface area? Assume that the animal's skin temperature is 32.0 , that the air temperature is 5.00 , and that has the same thermal conductivity as air. (b) What food intake will the animal need in one day to replace this heat transfer?
In 1986, a gargantuan iceberg broke away from the Ross Ice Shelf in Antarctica. It was approximately a rectangle 160 km long, 40.0 km wide, and 250 m thick. (a) What is the mass of this iceberg, given that the density of ice is 917kg/m3 ? (b) How much heat transfer (in joules) is needed to melt it? (c) How many years would it take sunlight alone to melt ice this thick, if the ice absorbs an average of 100W/m2, 12.00 h per day?
(a) Calculate the rate of heat conduction through a double-paned window that has a 150-m2 area and is made of two panes of 0.800 cm-thick glass separated by a 1.00 cm air gap. The inside surface temperature is 15.0 C, while that on the outside is 10.0 OC. (Hint: There are identical temperature drops across the two glass panes. First find these and then the temperature drop across the air gap. This problem ignores the increased heat transfer in the air gap due to convection.) (b) Calculate the rate of heat conduction through a 1.60-cm-thick window of the same area and with the same temperatures. Compare your answer with that for part (a).
(a) If a 500mL glass beaker is filled to the brim with ethyl alcohol at a temperature of 500C, how much will overflow when its temperature reaches 210C ? (b) How much less water would overflow under the same conditions?
(a) Estimate the specific heat capacity of sodium from the Law of Dulong and Petit. The molar mass of sodium is 23.0 g/mol. (b) What is the percent error of your estimate from the known value, 1230 J/kg ? `
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.
(a) A firewalker runs across a bed of hot coals without sustaining burns. Calculate the heat transferred by conduction into the sole of one foot of a firewalker given that the bottom of the foot is a 3.00-mm-thick callus with a conductivity at the low end of the range for wood and its density is 300kg/m3. The area of contact is 25.0cm2, the temperature of the coals is 700C, and the time in contact is 1.00 s. (b) What temperature increase is produced in the 25.0cm3 of tissue affected? (c) What effect do you think this will have on the tissue, keeping in mind that a callus is made of dead cells?
In 1986, an enormous iceberg broke away from the Ross Ice Shelf in Antarctica. It was an approximately rectangular prism 160 km long, 40.0 kin wide, and 250 m thick. (a) What is the mass of this iceberg, given that the density of ice is 917 kg/m3? (b) How much heat transfer (in joules) is needed to melt it? (c) How many years would it take sunlight alone to melt ice this thick, if the ice absorbs an average of 100 W/m2, 12.00 h per day?
(a) At what temperature do the Fahrenheit and Celsius scales have the same numerical value? (b) At what temperature do me Fahrenheit and Kelvin scales have the same numerical value?
What is me Fahrenheit temperature of a person with at 39.0°C fever?
A granite ball of radius 2.00 m and emissivity 0.450 is heated to 135C. (a) Convert the given temperature to Kelvin. (b) What is the surface area of the ball? (c) If the ambient temperature is 25.0C, what net power does the ball radiate?
(a) Calculate the R-value of a thermal window made of two single panes of glass each 0.125 in. thick and separated by a 0.230-in. air space. (b) By what factor is the transfer of energy by heat through the window reduced by using the thermal window instead of the single-pane window? Include the contributions of inside and outside stagnant air layers.