A certain double-pane window consists of two glass sheets, each 80 cm x 80 cm x 0.30 cm, separated by a 0.30-cm stagnant air space. The indoor surface temperature is 20 °C, while the outdoor surface temperature is exactly 0°C. How much heat passes through the window each second? k7 = 0.84 W/K -m for glass and about 0.080 W/K•m for air. Ans. 69 cal/s

A certain double-pane window consists of two glass sheets, each 80 cm x 80 cm x 0.30 cm, separated by a 0.30-cm stagnant air space. The indoor surface temperature is 20 °C, while the outdoor surface temperature is exactly 0°C. How much heat passes through the window each second? k7 = 0.84 W/K -m for glass and about 0.080 W/K•m for air. Ans. 69 cal/s

College Physics

10th Edition

ISBN:9781285737027

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter11: Energy In Thermal Processes

Section: Chapter Questions

Problem 9WUE: A granite ball of radius 2.00 m and emissivity 0.450 is heated to 135C. (a) Convert the given...

See similar textbooks

Similar questions

(a) The number of kilocalories in food is determined by calorimetry techniques in which the food is burned and the amount of heat transfer is measured. How many kilocalories per gram ale there in a 5.00-g peanut if the energy from burning it is transferred to 0. 500 kg of water held in a 0.100-kg aluminum cup, causing a 54.9- temperature increase? Assume the process takes place in an ideal calorimeter, in other words a perfectly insulated container. (b) Compare your answer to the following labeling information found on a package of dry roasted peanuts: a sewing of 33 g contains 200 calories. Comment on whether the values are consistent.
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) If the partial pressure of water vapor is 8.05 torr, what is the dew point? (760 torr = I atm 101, 325 Pa) (b) On a warn day when the air temperature is 35 and the dew point is 25 , what are the partial of the water in the air and the relative humidity?
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 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 high-end gas stove usually has at least one burner rated at 14 000 Btu/h. (a) If you place a 0.25-kg aluminum pot containing 2.0 liters of water at 20.C on this burner, how long will it take to bring the water to a boil, assuming all the heat from the burner goes into the pot? (b) Once boiling begins how much time is required to boil all the water out of the pot?
A glass windowpane in a home is 0.620 cm thick and has dimensions of 1.00 in 2.00 in. On a certain day, the temperature of the interior surface of the glass is 25.0C and the exterior surface temperature is 0C. (a) What is the rate at which energy is transferred by heat through the glass? (b) How much energy is transferred through the window in one day, assuming the temperatures on the surfaces remain constant?
A picture window has dimensions of 1.34 m by 2.65 m and is made of glass 5.93 mm thick. On a winter day, the outside temperature is -20°C, while the inside temperature is a comfortable 19.5°C. At what rate is heat being lost through the window by conduction? kglass = 0.80 W/m.K Round your answer to 2 decimal places.
A 450 g metal cube which is originally at 110 degree(s) C oven is dropped into 0.003 m3 of water in a at 70 degrees Celcuis in an insulated cup. After both water and cube reached thermal equilibrium, the final temp is 78 degrees Celsius. What is the specific heat capacity of the uknown metal cube? cWater= 4200 j/kgK cCube=? A. 2800 j/kgk B. 7000 j/kgk C. 6500 j/kgk D. 5100 j/kgk E. None
A Styrofoam cooler has total wall area (including the lid) of 0.80m2 and wall thickness 2.0 cm. It is filled with ice, water, and cans of Omni-Cola, all at 0°C. What is the rate of heat flow into the cooler if the temperature of the outside wall is 30°C.? How much ice melts in 3 hours? Ksytrofoam=0.027 W/m-K A. 34.2 W , 1.04 kg B. 32.4 W , 1.04 kg C. 32.4 W , 1.40 kg D. 34.2 W , 1.40 kg
A rectangular window in a home has a length of 1.5 m and a height of 0.80 m. If the window allows heat to escape from the home at a rate of 2,000 watts, how thick must the window be if the inside temperature of the home is 220 C and the outside temperature is 3.00C? (Assume that the coefficient of thermal conduction of glass is 0.80 W/mK.) a. 7.1 mm b. 124 mm c. 9.1 mm d. 8.1 mm e. 11 mm
A Thermopane window of area 5 m² is con- structed of two layers of glass, each 4.4 mm thick separated by an air space of 3 mm. If the inside is at 11°C and the outside is at -24°C, what is the heat loss through the window? The thermal conductivity of glass is 0.8 W/m .° C and of air is 0.0234 W/m .° C. Answer in units of kW.