21st Century Astronomy
6th Edition
ISBN: 9780393428063
Author: Kay
Publisher: NORTON
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Chapter 15, Problem 22QP
To determine
Reason why low density gases are hot and dense gases are cold.
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A cloud of gas has a temperature of 5,000 K.
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What is the wavelength in micrometers of peak emission for a black body at 33.5°C? (c = 3.0 × 108 m/s, Wien displacement law constant is 2.9 × 10-3 m ∙ K, σ = 5.67 × 10-8 W/m2 ∙ K4). Please give your answer with one decimal place.
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Chapter 15 Solutions
21st Century Astronomy
Ch. 15.1 - Prob. 15.1CYUCh. 15.2 - Prob. 15.2CYUCh. 15.3 - Prob. 15.3CYUCh. 15.4 - Prob. 15.4CYUCh. 15 - Prob. 1QPCh. 15 - Prob. 2QPCh. 15 - Prob. 3QPCh. 15 - Prob. 4QPCh. 15 - Prob. 5QPCh. 15 - Prob. 6QP
Ch. 15 - Prob. 7QPCh. 15 - Prob. 8QPCh. 15 - Prob. 9QPCh. 15 - Prob. 10QPCh. 15 - Prob. 11QPCh. 15 - Prob. 12QPCh. 15 - Prob. 13QPCh. 15 - Prob. 14QPCh. 15 - Prob. 15QPCh. 15 - Prob. 16QPCh. 15 - Prob. 17QPCh. 15 - Prob. 18QPCh. 15 - Prob. 19QPCh. 15 - Prob. 20QPCh. 15 - Prob. 21QPCh. 15 - Prob. 22QPCh. 15 - Prob. 23QPCh. 15 - Prob. 24QPCh. 15 - Prob. 25QPCh. 15 - Prob. 26QPCh. 15 - Prob. 27QPCh. 15 - Prob. 28QPCh. 15 - Prob. 29QPCh. 15 - Prob. 30QPCh. 15 - Prob. 31QPCh. 15 - Prob. 32QPCh. 15 - Prob. 33QPCh. 15 - Prob. 35QPCh. 15 - Prob. 36QPCh. 15 - Prob. 37QPCh. 15 - Prob. 38QPCh. 15 - Prob. 39QPCh. 15 - Prob. 40QPCh. 15 - Prob. 41QPCh. 15 - Prob. 42QPCh. 15 - Prob. 43QPCh. 15 - Prob. 44QPCh. 15 - Prob. 45QP
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- Interstellar dust is found to be at a temperature of 1000 K. At what wavelength will be the radiations?arrow_forwardA distant galaxy is observed with a spectrometer. This galaxy produces an emission line that is identified as a Hydrogen transition that normally has a wavelength of 21 cm. For this galaxy, however, the emission line is observed at a wavelength of 33 cm. How fast is this galaxy moving away from us in units of km/s [round off your answer to 1 km/s]arrow_forwardConsider a star for which the stellar power per unit area at distance 1 AU from the star is 3.7 kW/m^2. Assume the radius of the star is 0.005 AU (similar to Sol). What is the surface temperature of the star?arrow_forward
- What are Weakly Interacting Gases ?arrow_forwardSuppose we detect red photons at 656 nm emitted by electrons dropping from the n = 3 to the n = 2 orbital in hydrogen. The hydrogen is in an interstellar cloud at 5000k. If the cloud were heted to 10000 K, what would be the wavelength of the photons emitted by the transition? a) 328 nm b) 656 nm c) 1312 nm d) 658 nm e) 654 nmarrow_forwardThe relationship between the average luminosity and pulsation period for Cepheid variable stars can be written L = L⊙P3.7, where the period P is measured in days. A cepheid variable is observed in a distant galaxy, and is determined to have a pulsation period of 50 days. The average flux received from this star is measured to be 2.14×10−16Wm−2. Determine the distance to the galaxy and express your answer in units of Mpc.arrow_forward
- Astronomers can determine the heat of various areas of the universe by making observations about energy they emit. Gamma rays can be found in areas where there is a lot of star formation occurring. What would you guess about the temperature of these areas? Explain why.Do you think there would be a lot of particles present? Explain why.arrow_forwardDuring a free-fall collapse, a molecular cloud contracts, fragmenting into pieces. Each fragment collapses further at a temperature of ~176 K. Find the wavelength in nanometers at which the cloud will emit blackbody radiation most intensely.arrow_forwardHello. I need help solving ( 9 & 10) with explanations, it goes with the diagram above. Please and thank you.arrow_forward
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