Problem 6: Your temperature is 98 °F and your environment's 32 °F and you are wearing poorly insulated clothes. Assuming you are a blackbody (i.e. an ideal absorber and an ideal emitter), then you lose energy via radiation with a power of, (assume for simplicity that your radiating area is 2.0 m² and take your emissivity e to be 1). a) 2.1×10² W b) 4.1x10² W c) 6.3x10² W d) 1.04×10³ W

Problem 6: Your temperature is 98 °F and your environment's 32 °F and you are wearing poorly insulated clothes. Assuming you are a blackbody (i.e. an ideal absorber and an ideal emitter), then you lose energy via radiation with a power of, (assume for simplicity that your radiating area is 2.0 m² and take your emissivity e to be 1). a) 2.1×10² W b) 4.1x10² W c) 6.3x10² W d) 1.04×10³ W

University Physics Volume 2

18th Edition

ISBN:9781938168161

Author:OpenStax

Publisher:OpenStax

Chapter2: The Kinetic Theory Of Gases

Section: Chapter Questions

Problem 40P: What is the average kinetic energy in joules of hydrogen atoms on the 5500 surface of the Sun? (b)...

See similar textbooks

Similar questions

The total power emitted by a spherical black body of radius Rat a temperature T is P,. R Let P, be the total power emitted by another spherical black body of radius kept at 2 temperature 27T . The ratio, is (Give your answer upto two decimal places) P2
A child has a temperature of 101°F. If her total skin area is 19 m², find the energy loss per second due to radiation, as- suming the emissivity is 1. Assume the room temperature is 70°F. The Stephan-Boltzmann constant is 5.6696 × 10-8 w/m² · Kª . 2 Answer in units of W.
Consider a small spherical blackbody (with emissivity of e = 1) of radius 4.5 cm. %D Hint a. When this blackbody is at room temperature (T' of the radiation emitted by the body? Ignore any radiation absorbed by the blackbody and only consider the power emitted. 293 K or about 20°C), what is the total power The total power of the radiation emitted by the body is W. b. Suppose this blackbody is heated to a very high temperature (say, about 1000 K). What is the total power of the radiation emitted by the body now? The total power of the radiation emitted by the body is W. As you will see later in your future physics courses, the total power emitted is not the only thing that changes (for example, the color of the blackbody changes). But this will be more properly covered when you study quantum mechanics.
A typical doughnut contains 2g of protein, 17g of carbohydrates, and 7g of fat. a.Find the total calories absorbed for takingthree doughnuts? b.Consider a person with skin area of 1.3b m2were subjected into an intense radiation receives heat rate of 300 Cal/hr. If the person has emissivity e = 60. Find the angle of incidentNote: 1 Cal = 4.184J
A cube of edge length 6.0 * 10-6 m, emissivity 0.75, and temperature -100C floats in an environment at -150C.What is the cube’s net thermal radiation transfer rate?
Imagine choosing between two winter jackets. Assume you have access to a heat-generating mannequin with variable heat output. Insulation is comparable to (TB – TA)/M in the chapter 10 calculation. (This is a generic insulating equation.) How would you quantify the two jackets' insulation?
A sphere of radius 4.3 mm is at 3499 K. Calculate the rate of radiation of energy (in W) by the sphere, if its emissivity is 1.
The next four questions use this description. Our Sun has a peak emission wavelength of about 500 nm and a radius of about 700,000 km. Your dark-adapted eye has a pupil diameter of about 7 mm and can detect light intensity down to about 1.5 x 10-11 W/m2. Assume the emissivity of the Sun is equal to 1. First, given these numbers, what is the surface temperature of the Sun in Kelvin to 3 significant digits? What is the power output of the Sun in moles of watts? (in other words, take the number of watts and divide it by Avogadro's number) Assuming that all of the Sun's power is given off as 500 nm photons*, how many photons are given off by the Sun every second? Report your answer to the nearest power of 10 (e.g. if you got 7 x 1024, give your answer as 25).
We can use Stefan-Boltzmann Law, P = o AeT“, to produce a very rough estimation of temperature of the Earth. Follow the steps below to estimate the temperature of the Earth. At the radius of the Earth's orbit (1 astronomical unit away from the Sun), the thermal radiation from the Sun has an intensity of about S = 1370 W/m², known as the "solar constant." a. In terms of solar constant S and radius of the Earth R, what is the total solar power (Pn) incident on and absorbed by the Earth? Assume that Earth can be treated like a blackbody and will absorb all radiation incident on it. Hint for (a) Pin Give your answer in terms of S, R, and other numerical constants (spell out Greek characters, i.e. "pi" for T). the Earth rises, the power emitted by the Earth (Pout) increases. Give an b. As the temperature expression for power emitted by the Earth, in terms of its radius and other constants (see some of the constants used in Stefan-Boltzmann Law). Hint for (b) Pout Give your answer in terms…
We can use Stefan-Boltzmann Law, P = o AeT“, to produce a very rough estimation of temperature of the Earth. Follow the steps below to estimate the temperature of the Earth. At the radius of the Earth's orbit (1 astronomical unit away from the Sun), the thermal radiation from the Sun has an intensity of about S = 1370 W/m², known as the "solar constant." a. In terms of solar constant S and radius of the Earth R, what is the total solar power (Pin) incident on and absorbed by the Earth? Assume that Earth can be treated like a blackbody and will absorb all radiation incident on it. Hint for (a) Pin Give your answer in terms of S, R, and other numerical constants (spell out Greek characters, i.e. "pi" for T). b. As the temperature of the Earth rises, the power emitted by the Earth (Pout) increases. Give an expression for power emitted by the Earth, in terms of its radius and other constants (see some of the constants used in Stefan-Boltzmann Law). Hint for (b) Pout Give your answer in…
The next four questions use this description. Our Sun has a peak emission wavelength of about 500 nm and a radius of about 700,000 km. Your dark-adapted eye has a pupil diameter of about 7 mm and can detect light intensity down to about 1.5 x 10-11 W/m². Assume the emissivity of the Sun is equal to 1. First, given these numbers, what is the surface temperature of the Sun in Kelvin to 3 significant digits? 5,796
2.A solar collector with an area of 1.5 m2 is installed on the rooftop of a house. Assume that the radiative encrgy amiving from the sun is 1000 Wm. The collector reflecis 10% of the enengy arriving on is surfice. Also, the collector is not perfectly insulated, and losses occur The collector has a heat transfer coefficient h of 2 Wmx The side arcas of the collector are assumed to be negligible. The ambient temperature is 20 °C and the collector is assumed to be at a temperature of 50 "c. Consider that this temperature is constant throughout the whole collector The collector is assumed to behave like a black body. a) What is the power output of the collector? b) What percentage of the total losses is caused by radiation?