Figure P39.4 shows the spectrum of light emitted by a firefly. (a) Determine the temperature of a black body that would emit radiation peaked at the same wavelength. (b) Based on your result, explain whether firefly radiation is blackbody radiation. 1.0 0.8 0.6 0.4 0.2 0.2 F 400 500 600 Wavelength (nm) Relative in tensity

Figure P39.4 shows the spectrum of light emitted by a firefly. (a) Determine the temperature of a black body that would emit radiation peaked at the same wavelength. (b) Based on your result, explain whether firefly radiation is blackbody radiation. 1.0 0.8 0.6 0.4 0.2 0.2 F 400 500 600 Wavelength (nm) Relative in tensity

Physics for Scientists and Engineers with Modern Physics

10th Edition

ISBN:9781337553292

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter39: Introduction To Quantum Physics

Section: Chapter Questions

Problem 4P

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Similar questions

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?
Show that Stefan’s law results from Planck’s radiation law. Hin: To compute the total power of blackbody radiation emitted across the entire spectrum of wavelengths at a given temperature, integrate Planck’s law over the entire spectrum P(T)=0I(,T)d. Use the substitution x=hckT and the tabulated value of the integral 0dx x 3( e x 1)=415
What is the momentum of a 589-nm yellow photon?
(a) Calculate the number of photoelectrons per second that are ejected from a 1.00-mm2 area of sodium metal by a 500-nm radiation with intensity I .30kW/m2 (the intensity of sunlight above Earth’s atmosphere). (b) Given the work function of the metal as 2.28 eV, what power is carried away by these photoelectrons?
A 900-W microwave generator in an oven generates energy quanta of frequency 2560 MHz. (a) How many energy quanta does it emit per second? (b) How many energy quanta must be absorbed by a pasta dish placed in the radiation cavity to increase its temperature by 45.0 K? Assume that the dish has a mass of 0.5 kg and that its specific heat is 0.9 kcal/kg • K. (c) Assume that all energy quanta emitted by the generator are absorbed by the pasta dish. How long must we wait until the dish in (b) is ready?
Consider a black body of surface area 20.0 cm2 and temperature 5 000 K. (a) How much power does it radiate? (b) At what wavelength does it radiate most intensely? Find the spectral power per wavelength interval at (c) this wavelength and at wavelengths of (d) 1.00 nm (an x- or gamma ray), (e) 5.00 nm (ultraviolet light or an x-ray), (f) 400 nm (at the boundary between UV and visible light), (g) 700 nm (at the boundary between visible and infrared light), (h) 1.00 mm (infrared light or a microwave), and (i) 10.0 cm (a microwave or radio wave). ( j) Approximately how much power does the object radiate as visible light?
How much energy does a photon of yellow light have if it’s wavelength is 600nm?
What are the energy and momentum of a photon of red light of wavelength 620 nanometers (nm)? What is the wavelength (in nm) of photons of energy 2.40 eV?
A satellite in Earth orbit maintains a panel of solar cells of area 2.60 m2 perpendicular to the direction of the Sun’s light rays. The intensity of the light at the panel is 1.39 kW/m2. (a) At what rate does solar energy arrive at the panel? (b) At what rate are solar photons absorbed by the panel? Assume that the solar radiation is monochromatic, with a wavelength of 550 nm, and that all the solar radiation striking the panel is absorbed. (c) How long would it take for a “mole of photons” to be absorbed by the panel?
A photon with a wavelength of 0.07 nm is Compton scattered through an angle of 163o. (a) What is the energy of he incident photon? (b) What is the wavelength of the scattered photon? (c) How much energy is given to the electron? (d) What is the recoil speed of the electron?
Figure P27.45 shows the spectrum of light emitted by a firefly. (a) Determine the temperature of a blackbody that would emit radiation peaked at the same frequency. (b) Based on your result, explain whether firefly radiation is blackbody radiation.
Diffraction effects become significant when the width of an aperture is comparable to the wavelength of the waves being diffracted. (a) At what speed will the de Broglie wavelength of a 65-kg student be equal to the 0.76-m width of a doorway? (b) At this speed, how much time will it take the student to travel a distance of 1.0 mm? (For comparison, the age of the universe is approximately 4 * 10^17 s.)