Physics for Scientists and Engineers with Modern Physics
10th Edition
ISBN: 9781337553292
Author: Raymond A. Serway, John W. Jewett
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 39, Problem 49CP
(a)
To determine
To show that the power per unit area is
(b)
To determine
To show that Stephan-Boltzmann constant has value
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A blackbody is an object with a radiation spectrum that is dependent solely on its tempera-
ture. A blackbody spectrum (or spectral radiancy curve) is described by the Planck Radiation
Law.
(a)
i. Sketch the spectral radiancy curves for blackbodies with temperatures of T = 4000 K
and T = 6000 K, respectively. Describe the main differences between the two
curves in terms of the appropriate physical laws defined as a function of tempera-
ture.
ii. What is the wavelength at peak intensity for each blackbody? State the part of
the electromagnetic spectrum to which each wavelength belongs.
(b) Use the Planck Radiation Law to determine the power radiated per unit area between
the wavelengths A 500 nanometres and λ = 503 nanometres for the T 6000 K
blackbody. What fraction of the blackbody's radiancy lies in this wavelength range?
=
For the thermal radiation from an ideal blackbody radiator with a surface temperature of 2000 K, let Ic represent the intensity per unit wavelength according to the classical expression for the spectral radiancy and IP represent the corresponding intensity per unit wavelength according to the Planck expression.What is the ratio Ic/IP for a wavelength of (a) 400 nm (at the blue end of the visible spectrum) and (b) 200 mm (in the far infrared)? (c) Does the classical expression agree with the Planck expression in the shorter wavelength range or the longer wavelength range?
For a black body, the temperature and the wavelength of the emission maximum, Amax, are related by Wein's
Law, expressed as:
T/°C
λmax/nm
Values of Amax from a small pinhole in an electrically heated container were determined at a series of
temperatures. The results are given below. Deduce the value of Planck's constant.
1000
2181
c = 3.00 x 108 m/s
1500
1600
λmaxT =
2000
1240
k= 1.38 x 10-34 J-S
hc
4.965k
2500
1035
3000
878
3500
763
Chapter 39 Solutions
Physics for Scientists and Engineers with Modern Physics
Ch. 39.1 - Prob. 39.1QQCh. 39.2 - Prob. 39.2QQCh. 39.2 - Prob. 39.3QQCh. 39.2 - Prob. 39.4QQCh. 39.3 - Prob. 39.5QQCh. 39.5 - Prob. 39.6QQCh. 39.6 - Prob. 39.7QQCh. 39 - Prob. 1PCh. 39 - Prob. 2PCh. 39 - Prob. 3P
Ch. 39 - Prob. 4PCh. 39 - Prob. 5PCh. 39 - Prob. 6PCh. 39 - Prob. 8PCh. 39 - Prob. 9PCh. 39 - Prob. 10PCh. 39 - Prob. 11PCh. 39 - Prob. 12PCh. 39 - Prob. 13PCh. 39 - Prob. 15PCh. 39 - Prob. 16PCh. 39 - Prob. 17PCh. 39 - Prob. 18PCh. 39 - Prob. 19PCh. 39 - Prob. 20PCh. 39 - Prob. 22PCh. 39 - Prob. 23PCh. 39 - Prob. 24PCh. 39 - Prob. 25PCh. 39 - Prob. 26PCh. 39 - Prob. 27PCh. 39 - Prob. 30PCh. 39 - Prob. 31PCh. 39 - Prob. 32PCh. 39 - Prob. 33PCh. 39 - Prob. 35PCh. 39 - Prob. 37PCh. 39 - Prob. 38PCh. 39 - Prob. 39PCh. 39 - Prob. 40APCh. 39 - Prob. 41APCh. 39 - Prob. 43APCh. 39 - Prob. 44APCh. 39 - Prob. 45APCh. 39 - Prob. 46APCh. 39 - Prob. 47CPCh. 39 - Prob. 48CPCh. 39 - Prob. 49CPCh. 39 - Prob. 50CP
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- Find x value.arrow_forwardThrough what potential difference ΔVΔV must electrons be accelerated (from rest) so that they will have the same wavelength as an x-ray of wavelength 0.130 nmnm? Use 6.626×10−34 J⋅sJ⋅s for Planck's constant, 9.109×10−31 kgkg for the mass of an electron, and 1.602×10−19 CC for the charge on an electron. Express your answer using three significant figures. =89.0 V Through what potential difference ΔVΔV must electrons be accelerated so they will have the same energy as the x-ray in Part A? Use 6.626×10−34 J⋅sJ⋅s for Planck's constant, 3.00×108 m/sm/s for the speed of light in a vacuum, and 1.602×10−19 CC for the charge on an electron. Express your answer using three significant figures. Second question is what I need help on! Thanks!arrow_forwardWhen light with a frequency f1 = 547.5 THz illuminates a metal surface, the most energetic photoelectrons have 1.260 x 10^-19 J of kinetic energy. When light with a frequency f2 = 738.8 THz is used instead, the most energetic photoelectrons have 2.480 x 10^-19 J of kinetic energy. Using these experimental results , determine the approximate value of Planck's constant.arrow_forward
- Solar radiation falls on Earth's surface at a rate of 1900 W/m². Assuming that the radiation has an average wavelength of 580 nm, how many photons per square meter per second fall on the surfaces? The speed of light is 3 × 10° m/s and Planck's constant is 6.62607 × 10-34 J. s. Answer in units of photon/m² · s. 2arrow_forwardPART A: A metal surface is illuminated with photons with a frequency f=1.5×10^15 Hz. The stopping potential for electrons photoemitted from the surface is 3.6 V. What is the work function of the metal? Answer= 2.6 eV PART B: A certain metal has a work function ϕ. What is the maximum photon wavelength that will produce photoemission? Express your answer in terms of ϕ,Planck's constant h, and the speed of light c. Answer= λ =hc/ϕ PART C: Electrons emitted from a metal surface with a work function ϕ = 2.8 eV have a corresponding stopping potential of V0 = 3.6 V. If a metal with a work functionϕnew = 2.2 eV is illuminated by the same wavelength of light, what will be the new stopping potential? Express your answer with the appropriate units. *Please answer Part C*arrow_forwardA neutron of mass 1.675 × 10-27 kg has a de Broglie wavelength of 7.8x10-12 m. What is the kinetic energy (in eV) of this non-relativistic neutron? Please give your answer with two decimal places. 1 eV = 1.60 × 10-19 J, h = 6.626 × 10-34 J ∙ s.arrow_forward
- Light of frequency 0.790 × 10^15 Hz illuminates a sodium surface. The ejected photoelectrons are found to have a maximum kinetic energy of 1.01 eV. Calculate the work function of sodium. Planck’s constant is 6.63 × 10^−34 J · s .arrow_forwardIn a particular photoelectric experiment, a stopping potential of 2.1 V is measured when ultraviolet light with a wavelength of 290 nm is incident on a metal. Given the light of speed c = 3.0 x 108 m/s and Planck constant h = 6.625 x 10-34 J. s or 4.14 × 10-15 eV.s %3D (a) Describe and illustrate the photoelectric experiment and explain why it cannot be explained by classical physics. (b) Using the same setup and metal, determine the stopping potential if blue light with a wavelength of 440 nm is used, instead of the ultraviolet light. (c) Using the same setup and metal, describe what happened if a red light with a wavelength of 620 nm is used, instead of the ultraviolet light.arrow_forwardPlanck's radiation law can be written ux = 8лhc 1 25 eßhc/2-1 Show that the wavelength corresponding to the maximum energy density of the radiation fulfills the condition λmax T = . constant What is this constant? (This result is known as Wien's transition law.) Tip: you can solve the constant approximation by e.g. iterating an equation of the form Xn = 5 (1-e¯Xn-1) with a suitable initial value x1.arrow_forward
- Consider a black body of surface area 22.0 cm² and temperature 5700 K. (a) How much power does it radiate? 131675.5 W (b) At what wavelength does it radiate most intensely? 508.421 nm (c) Find the spectral power per wavelength at this wavelength. Remember that the Planck intensity is "intensity per unit wavelength", with units of W/m³, and "power per unit wavelength" is equal to that intensity times the surface area, with units of W/m 131.5775 Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. W/marrow_forwardIn a photoelectric experiment it is found that a stopping potential of 1.00 V is needed to stop all the electrons when incident light of wavelength 225 nm is used and 1.5 V is needed for light of wavelength 207 nm. From these data determine Planck's constant. (Enter your answer, in eV s, to at least four significant figures.) 4.2367e-15 X ev s From these data determine the work function (in eV) of the metal. 4.6 X evarrow_forwardIn an experiment on the photoelectric effect, a metal is illuminated by visible light of different wavelengths. A photoelectron has a maximum kinetic energy of 0.9 eV when red light of wavelength 640 nm is used. With blue light of wavelength 420 nm, the maximum kinetic energy of the photoelectron is 1.9 eV. Use this information to calculate an experimental value for the Planck constant h. [arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
University Physics Volume 3PhysicsISBN:9781938168185Author:William Moebs, Jeff SannyPublisher:OpenStax
Physics for Scientists and Engineers with Modern ...
Physics
ISBN:9781337553292
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
University Physics Volume 3
Physics
ISBN:9781938168185
Author:William Moebs, Jeff Sanny
Publisher:OpenStax