Homework Answers
Add Answer to:
The rate of heat transfer by emitted radiation is determined by the Stefan-Boltzmann law of radiation...
How much power (power is the energy per second) is radiated by the person
Radiation of Energy The rate of heat transfer by emitted radiation is determined by the Stefan-Boltzmann law of radiation: = aeAT4 where o 5.67x10-8 J/s - m2 K is the Stefan-Boltzmann constant, A is the surface area of the object, and T is its absolute temperature in kelvin. The symbol e stands for the emissivity of the object, which is a measure of how well it radiates An ideal jet-black (or black body) radiator has e 1,whereas a perfect reflector has...
Absorb Incident radiant onorgy Reflected Emitted Absorbed Retained Black Black Incident radiant energy Reflected Emitte Retained...
Absorb Incident radiant onorgy Reflected Emitted Absorbed Retained Black Black Incident radiant energy Reflected Emitte Retained Absorbed Silver coated Silver coated A person with a surface area of 1.20 m2, and a skin temperature of 27 °C, is in a room that is at a temperature of 17.6 °C. The emissivity of the skin is 0.895, The Stefan-Boltzmann constant is 5.67 x 10-8 W/(m2K). (a) How much energy is radiated by the person in 1 minute? Keep 2 decimal places....
Radiation heat transfer: Two perfectly black surfaces (each with emissivity ε = 1.0) are constructed such...
Radiation heat transfer: Two perfectly black surfaces (each with emissivity ε = 1.0) are constructed such that all the radiant energy leaving a surface at 800 °C (1073 K) reaches the other surface. The temperature of the other surface, with area A = 2 m2, is maintained at 250 °C (523 K). Using the formula Q = ε σ A (THot4 – TCold4) calculate the heat transfer (in kW) of the surface maintained at 800 °C. The Stefan-Boltzmann constant, σ...
eq 4.25 eq 4.27 The Stefan-Boltzmann law can be employed to estimate the rate of radiant...
eq 4.25
eq 4.27
The Stefan-Boltzmann law can be employed to estimate the rate of radiant energy loss from a surface, as in H = AeoT4 where H is in watts, A = the surface area (m2), e = the emissivity (dimensionless quantity that characterizes the rate of heat loss from a material versus a perfect radiator, or blackbody radiator), σ = the Stefan-Boltzmann constant (5.670367 × 10-8 W·m「"K-4), and T = absolute temperature (K). a) Employ equation (4.25) from...
Which of the following statements concerning radiation heat transfer is false? The radiation emitted by a...
Which of the following statements concerning radiation heat transfer is false? The radiation emitted by a body is proportional to the fourth power of its absolute temperature. For a body of particular size and temperature, the maximum energy is emitted b a black body For an opaque body, the sum of absorptivity and reflectivity is always equal to unity. Radiation is always negligible at room temperature. None of these statements is false.
In this problem you will consider the balance of thermal energy radiated and absorbed by a...
In this problem you will consider the balance of thermal energy radiated and absorbed by a person. Assume that the person is wearing only a skimpy bathing suit of negligible area. As a rough approximation, the area of a human body may be considered to be that of the sides of a cylinder of length L=2.0m and circumference C=0.8m. For the Stefan-Boltzmann constant use σ=5.67×10−8W/m2/K4. Part A If the surface temperature of the skin is taken to be T_body=30∘C, how...
The emissivity of the human skin is 97.0 percent. Use 35.0 °C for the skin temperature...
The emissivity of the human skin is 97.0 percent. Use 35.0 °C for the skin temperature and approximate the human body by a rectangular block with a height of 1.81 m, a width of 40.5 cm and a length of 32.0 cm. Calculate the power emitted by the human body. 1.430x103 w You are correct. Your receipt no. is 158-4715 Previous Tries Fortunately our environment radiates too. The human body absorbs this radiation with an absorbance of 97.0 percent, so...
In this problem you will consider the balance of thermal energy radiated and absorbed by a...
In this problem you will consider the balance of thermal energy radiated and absorbed by a person in a room. The rate of heat transfer from radiation is: ΔQΔt=eσA(T42−T41)=eσAT42−eσAT41. This equation has two terms which represent the rate of absorption from the room (a gain) and the rate of radiation into the room (a loss). In this problem, we will consider these two terms separately. Assume that the area of a human body may be considered to be that of...
(33%) Problem 3: Warm blooded animals are home otherm that is, they maintain an approximately constant...
(33%) Problem 3: Warm blooded animals are home otherm that is, they maintain an approximately constant body temperature. (For humans it's about 37°C.) When they are in an environment that is below their optimum temperature, they use energy derived from chemical reactions within their bodies to warm them up One of the ways that animals lose energy to their environment is through radiation. Every object emits electromagnetic radiation that depends on its temperature. For very hot objects like the sun,...
2. The average person has 1.4 m2 of skin at a skin temperature of roughly 305...
2. The average person has 1.4 m2 of skin at a skin temperature of roughly 305 K (90°F) Consider the average person to be an ideal radiator standing in a room at a temperature of 293 K (68°F) (a) Calculate the power (energy per uni i) radiated by the average person in the form of blackbody radiation; express your answer in erg s-1. What is the person's "wattage"? (1 W = 107 erg s-1) Compare this to a typical incandescent...
Radiation of Energy The rate of heat transfer by emitted radiation is determined by the Stefan-Boltzmann law of radiation: = aeAT4 where o 5.67x10-8 J/s - m2 K is the Stefan-Boltzmann constant, A is the surface area of the object, and T is its absolute temperature in kelvin. The symbol e stands for the emissivity of the object, which is a measure of how well it radiates An ideal jet-black (or black body) radiator has e 1,whereas a perfect reflector has...
Absorb Incident radiant onorgy Reflected Emitted Absorbed Retained Black Black Incident radiant energy Reflected Emitte Retained Absorbed Silver coated Silver coated A person with a surface area of 1.20 m2, and a skin temperature of 27 °C, is in a room that is at a temperature of 17.6 °C. The emissivity of the skin is 0.895, The Stefan-Boltzmann constant is 5.67 x 10-8 W/(m2K). (a) How much energy is radiated by the person in 1 minute? Keep 2 decimal places....
eq 4.25
eq 4.27
The Stefan-Boltzmann law can be employed to estimate the rate of radiant energy loss from a surface, as in H = AeoT4 where H is in watts, A = the surface area (m2), e = the emissivity (dimensionless quantity that characterizes the rate of heat loss from a material versus a perfect radiator, or blackbody radiator), σ = the Stefan-Boltzmann constant (5.670367 × 10-8 W·m「"K-4), and T = absolute temperature (K). a) Employ equation (4.25) from...
Which of the following statements concerning radiation heat transfer is false? The radiation emitted by a body is proportional to the fourth power of its absolute temperature. For a body of particular size and temperature, the maximum energy is emitted b a black body For an opaque body, the sum of absorptivity and reflectivity is always equal to unity. Radiation is always negligible at room temperature. None of these statements is false.
The emissivity of the human skin is 97.0 percent. Use 35.0 °C for the skin temperature and approximate the human body by a rectangular block with a height of 1.81 m, a width of 40.5 cm and a length of 32.0 cm. Calculate the power emitted by the human body. 1.430x103 w You are correct. Your receipt no. is 158-4715 Previous Tries Fortunately our environment radiates too. The human body absorbs this radiation with an absorbance of 97.0 percent, so...
(33%) Problem 3: Warm blooded animals are home otherm that is, they maintain an approximately constant body temperature. (For humans it's about 37°C.) When they are in an environment that is below their optimum temperature, they use energy derived from chemical reactions within their bodies to warm them up One of the ways that animals lose energy to their environment is through radiation. Every object emits electromagnetic radiation that depends on its temperature. For very hot objects like the sun,...
2. The average person has 1.4 m2 of skin at a skin temperature of roughly 305 K (90°F) Consider the average person to be an ideal radiator standing in a room at a temperature of 293 K (68°F) (a) Calculate the power (energy per uni i) radiated by the average person in the form of blackbody radiation; express your answer in erg s-1. What is the person's "wattage"? (1 W = 107 erg s-1) Compare this to a typical incandescent...
Most questions answered within 3 hours.
-
Discuss the expected values of the information to
management and how the initial problem might be...
asked 2 minutes from now -
Consider the solubilities of a particular solute at two
different temperatures.
Temperature (∘C)
Solubility (g/100 g...
asked 17 minutes ago -
I have a self introduction speech for oral communication class
using Holidays as an analogy of...
asked 23 minutes ago -
2) A solenoid wound 205/m with a radius of 0.3 meters and a
length of 0.3...
asked 30 minutes ago -
create a C++ program which reads in a Social Security
number, a first name, a middle...
asked 32 minutes ago -
Manufacturing overhead was estimated to be $451,000 for the year
along with 20,500 direct labor hours....
asked 32 minutes ago -
a piece of gold has a volume of 37.0 mL. what should
the mass be if...
asked 48 minutes ago -
why are most training programs not evaluated?
please provide me with at least 250 words. Thank...
asked 43 minutes ago -
1. A student ran the following reaction in the laboratory at
632 K:
2HI(g)
->H2(g) +...
asked 46 minutes ago -
An engineer measures the frequencies of the audible standing
waves in an organ pipe. He finds...
asked 48 minutes ago -
The following financial statements and additional information
are reported.
IKIBAN INC.
Comparative Balance Sheets
June 30,...
asked 53 minutes ago -
What is the relationship between the variance and the standard
deviation?
Multiple Choice
Variance is the...
asked 59 minutes ago