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A cylindrical log 20 cm in diameter and 55 cm long is glowing red hot in a fireplace. |
Part A If it's emitting radiation at the rate of 38 kW , what is its temperature? The log's emissivity is essentially 1. Express your answer using two significant figures. |
![= 5s cm, 0-20 Cm, = 36kw .temperature of (og &AG T axo e | X2x0.2+ TX.2 x0.55] 5.67K10T 38 1 T=113 1.8 2 K T= 85 8.82](http://img.homeworklib.com/images/2e108900-5308-42cc-bbdb-95106917cff7.png?x-oss-process=image/resize,w_560)
A cylindrical log 20 cm in diameter and 55 cm long is glowing red hot in a fireplace. Part A If it's emitting...
A cylindrical tungsten filament 14.0 cm long with a diameter of 1.10 mm is to be used in a machine for which the temperature will range from room temperature (20 ∘C) up to 120 ∘C. It will carry a current of 12.5 A at all temperatures ( Resistivity of tungsten at 20 ∘C is 5.25×10−8Ω⋅m , the temperature coefficient of resistivity at 20 ∘C is 0.0045 ∘C−1 ) Part A What will be the maximum electric field in this filament?...
A cylindrical tungsten filament 15.0 cm long with a diameter of 1.10 mm is to be used in a machine for which the temperature will range from room temperature (20 ∘C) up to 120 ∘C. It will carry a current of 13.5 A at all temperatures ( Resistivity of tungsten at 20 ∘C is 5.25×10−8Ω⋅m , the temperature coefficient of resistivity at 20 ∘Cis 0.0045 ∘C−1 ) Part B What will be its resistance with that field? Express your answer...
The hot glowing surfaces of stars emit energy in the form of electromagnetic radiation. It is a good approximation to assume that the emissivity e is equal to 1 for these surfaces.Part AFind the radius RRigel of the star Rigel, the bright blue star in the constellation Orion that radiates energy at a rate of 2.7×10^31 W and has a surface temperature of 11,000 K. Assume that the star is spherical.Use σ=5.67×10^−8 W/m2⋅K4 for the Stefan-Boltzmann constant and express your...
The hot glowing surfaces of stars emit energy in the form of electromagnetic radiation. It is a good approximation to assume that the Emissivity e is equal to 1 for these surfaces. Find the radius RRigel of the star Rigel, the bright blue star in the constellation Orion that radiates energy at a rate of 2.7 x 1031 W and has a surface temperature of 11,000 K. Assume that the star is spherical Use σ = 5.67 × 10-8 w/m2-K4...
human body. Model a head as a 21-cm-diameter, 20-cm-tall cylinder with a flat top. If the body's surface temperature is 35 ∘C , what is the net rate of heat loss on a chilly 7 ∘C day? All skin, regardless of color, is effectively black in the infrared where the radiation occurs, so use an emissivity of 0.95. Express your answer to two significant figures and include the appropriate units.
A spherical pot of hot coffee contains 0.75 L of liquid (essentially water) at an initial temperature of 99 ∘C. The pot has an emissivity of 0.60, and the surroundings are at a temperature of 20.0∘C. Part A Calculate the coffee’s rate of heat loss by radiation. Express your answer to two significant figures and include the appropriate units. H H = 0.00W SubmitPrevious AnswersRequest Answer Incorrect; Try Again; 2 attempts remaining
An electric current passes through a metal strip 0.40 cm by 5.9 cm by 0.14 mm, heating it at the rate of 52 W. The strip has emissivity e = 1.0 and its surroundings are at 340 K. What will be the temperature of the strip if it's enclosed in (a) a vacuum bottle transparent to all radiation and (b) an insulating box with thermal resistance R = 7.5 K/W that blocks all radiation? Express your answer using two significant...
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A drinking straw 20 cm long and 3.0 mm in diameter stands
vertically in a cup of juice 8.0 cm in diameter. A section of straw
6.8 cm long extends above the juice. A child sucks on the straw,
and the juice level begins dropping at 2.2 mm/s .
By how much does the pressure in the child's mouth differ from
atmospheric pressure?
What is the greatest height above the water surface from which
the child could drink, assuming this...