University Physics with Modern Physics (14th Edition)
14th Edition
ISBN: 9780321973610
Author: Hugh D. Young, Roger A. Freedman
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 39, Problem 39.32E
(a)
To determine
What is the energy of each photon.in
(b)
To determine
The number of photons delivered per square millimeter to the blemish.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
Exposure to a sufficient quantity of ultraviolet light will redden the skin, producing erythema—a sunburn. The amount of exposure necessary to produce this reddening depends on the wavelength. For a 1.0 cm2 patch of skin, 3.7 mJ of ultraviolet light at a wavelength of 254 nm will produce reddening; at 300 nm wavelength, 13 mJ are required.a. What is the photon energy corresponding to each of these wavelengths?b. How many total photons does each of these exposures correspond to?c. Explain why there is a difference in the number of photons needed to provoke a response in the two cases.
Removing Birthmarks. Pulsed dye lasers emit light of wavelength 585 nm in 0.45 ms pulses to remove skin blemishes such as birthmarks. The beam is usually focused onto a circular spot 5.0 mm in diameter. Suppose that the output of one such laser is 20.0 W. (a) What is the energy of each photon, in eV? (b) How many photons per square millimeter are delivered to the blemish during each pulse?
A ruby laser emits an intense pulse of light that lasts a mere 10 ns . The light has a wavelength of 690 nm , and each pulse has an energy of 400 mJ .
How many photons are emitted in each pulse?
What is the rate of photon emission, in photons per second, during the 10 nsns that the laser is "on"?
Chapter 39 Solutions
University Physics with Modern Physics (14th Edition)
Ch. 39.2 - Prob. 39.2TYUCh. 39.3 - Prob. 39.3TYUCh. 39.4 - Prob. 39.4TYUCh. 39.5 - Prob. 39.5TYUCh. 39.6 - Prob. 39.6TYUCh. 39 - Prob. 39.1DQCh. 39 - Prob. 39.2DQCh. 39 - Prob. 39.3DQCh. 39 - When an electron beam goes through a very small...Ch. 39 - Prob. 39.5DQ
Ch. 39 - Prob. 39.6DQCh. 39 - Prob. 39.7DQCh. 39 - Prob. 39.8DQCh. 39 - Prob. 39.9DQCh. 39 - Prob. 39.10DQCh. 39 - Prob. 39.11DQCh. 39 - Prob. 39.12DQCh. 39 - Prob. 39.13DQCh. 39 - Prob. 39.14DQCh. 39 - Prob. 39.15DQCh. 39 - Prob. 39.16DQCh. 39 - Prob. 39.17DQCh. 39 - Prob. 39.18DQCh. 39 - Prob. 39.19DQCh. 39 - Prob. 39.20DQCh. 39 - Prob. 39.21DQCh. 39 - When you check the air pressure in a tire, a...Ch. 39 - Prob. 39.1ECh. 39 - Prob. 39.2ECh. 39 - Prob. 39.3ECh. 39 - Prob. 39.4ECh. 39 - Prob. 39.5ECh. 39 - Prob. 39.6ECh. 39 - Prob. 39.7ECh. 39 - Prob. 39.8ECh. 39 - Prob. 39.9ECh. 39 - Prob. 39.10ECh. 39 - Prob. 39.11ECh. 39 - Prob. 39.12ECh. 39 - Prob. 39.13ECh. 39 - Prob. 39.14ECh. 39 - Prob. 39.15ECh. 39 - Prob. 39.16ECh. 39 - Prob. 39.17ECh. 39 - Prob. 39.18ECh. 39 - Prob. 39.19ECh. 39 - Prob. 39.20ECh. 39 - Prob. 39.21ECh. 39 - Prob. 39.22ECh. 39 - Prob. 39.23ECh. 39 - Prob. 39.24ECh. 39 - Prob. 39.25ECh. 39 - Prob. 39.26ECh. 39 - Prob. 39.27ECh. 39 - Prob. 39.28ECh. 39 - Prob. 39.29ECh. 39 - Prob. 39.30ECh. 39 - Prob. 39.31ECh. 39 - Prob. 39.32ECh. 39 - Prob. 39.33ECh. 39 - Prob. 39.34ECh. 39 - Prob. 39.35ECh. 39 - Prob. 39.36ECh. 39 - Prob. 39.37ECh. 39 - Prob. 39.38ECh. 39 - Prob. 39.39ECh. 39 - Prob. 39.40ECh. 39 - Prob. 39.41ECh. 39 - Prob. 39.42ECh. 39 - Prob. 39.43ECh. 39 - Prob. 39.44ECh. 39 - Prob. 39.45ECh. 39 - Prob. 39.46ECh. 39 - Prob. 39.47ECh. 39 - Prob. 39.48ECh. 39 - Prob. 39.49ECh. 39 - Prob. 39.50PCh. 39 - Prob. 39.51PCh. 39 - Prob. 39.52PCh. 39 - Prob. 39.53PCh. 39 - Prob. 39.54PCh. 39 - Prob. 39.55PCh. 39 - Prob. 39.56PCh. 39 - Prob. 39.57PCh. 39 - Prob. 39.58PCh. 39 - Prob. 39.59PCh. 39 - An Ideal Blackbody. A large cavity that has a very...Ch. 39 - Prob. 39.61PCh. 39 - Prob. 39.62PCh. 39 - Prob. 39.63PCh. 39 - Prob. 39.64PCh. 39 - Prob. 39.65PCh. 39 - Prob. 39.66PCh. 39 - Prob. 39.67PCh. 39 - Prob. 39.68PCh. 39 - Prob. 39.69PCh. 39 - Prob. 39.70PCh. 39 - Prob. 39.71PCh. 39 - Prob. 39.72PCh. 39 - Prob. 39.73PCh. 39 - Prob. 39.74PCh. 39 - Prob. 39.75PCh. 39 - Prob. 39.76PCh. 39 - Prob. 39.77PCh. 39 - Prob. 39.78PCh. 39 - Prob. 39.79PCh. 39 - Prob. 39.80PCh. 39 - A particle with mass m moves in a potential U(x) =...Ch. 39 - Prob. 39.82PCh. 39 - Prob. 39.83PCh. 39 - DATA In the crystallography lab where you work,...Ch. 39 - Prob. 39.85PCh. 39 - Prob. 39.86CPCh. 39 - Prob. 39.87CPCh. 39 - Prob. 39.88PPCh. 39 - Prob. 39.89PPCh. 39 - Prob. 39.90PPCh. 39 - Prob. 39.91PP
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
- 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?arrow_forward(a) What is the ratio of power outputs by two microwave ovens having frequencies of 950 and 2560 MHz, if they emit the same number of photons per second? (b) What is the ratio of photons per second if they have the same power output?arrow_forwardA 400-nm laser beam is projected onto a calcium electrode. The power of the laser beam is 2.00 mW and the work function of calcium is 2.31 eV. (a) How many photoelectrons per second are ejected? (b) What net power is carried away by photoelectrons?arrow_forward
- What is the wavelength of (a) a 12-keV X-ray photon; (b) a 2.O-MeV y -ray photon?arrow_forwardA 600-nm light falls on a photoelectric surface and electrons with the maximum kinetic energy of 0.17 eV are emitted. Determine (a) the work function and (b) the cutoff frequency of the surface. (c) What is the stopping potential when the surface is illuminated with light of wavelength 400 nm?arrow_forwardAtoms can be ionized by thermal collisions, such as at the high temperatures found in the solar corona. One such ion is C+5, a carbon atom with only a single electron. (a) By what factor are the energies of its hydrogen-like levels greater than those of hydrogen? (b) What is the wavelength of the first line in this ion's Paschen series? (c) What type of EM radiation is this?arrow_forward
- A 200-W heater emits a 1.5-m radiation. (a) What value of the energy quantum does it emit? (b) Assuming that the specific heat of a 4.0-kg body is 0.83kcaI/kg • K, how many of these photons must be absorbed by the body to increase its temperature by 2 K? (c) How long does the heating process in (b) take, assuming that all radiation emitted by the heater gets absorbed by the body?arrow_forwardA laser with a power output of 2.00 mW at a 400-nm wavelength is used to project a beam of light onto a calcium photoelectrode. (a) How many photoelectrons leave the calcium surface per second? (b) What power is carried away by ejected photoelectrons, given that the work function of calcium is 2.31 eV? (c) Calculate the photocurrent. (d) If the photoelectrode suddenly becomes electrically insulated and the setup of two electrodes in the circuit suddenly starts to act like a 2.00-pF capacitor, how long will current flow before the capacitor voltage stops it?arrow_forwardThe work function for potassium is 2.26 eV. What is the cutoff frequency when this metal is used as photoelectrode? What is the stopping potential when for the emitted electrons when this photo electrode is exposed to radiation of frequency 1200 THz?arrow_forward
- (a) Calculate the number of photoelectrons per second ejected from a 1.00-mm2 area of sodium metal by 500-nm M radiation having an intensity of 1.30 kW/m2 (the intensity of sunlight above the Earth's atmosphere). (b) Given that the binding energy is 2.28 eV, what power is carried away by the electrons? (c) The electrons carry away less power than brought in by the photons. Where does the other power go? How can it be recovered?arrow_forwardThe wavelengths of visible light range from approximately 400 to 750 nm. What is the corresponding range of photon energies for visible light?arrow_forward(a) Calculate the velocity of an electron that has a wavelength of 1.00 m. (b) Through what voltage must the electron be accelerated to have this velocity?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningGlencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillUniversity Physics Volume 3PhysicsISBN:9781938168185Author:William Moebs, Jeff SannyPublisher:OpenStax
- College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegeModern PhysicsPhysicsISBN:9781111794378Author:Raymond A. Serway, Clement J. Moses, Curt A. MoyerPublisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Glencoe Physics: Principles and Problems, Student...
Physics
ISBN:9780078807213
Author:Paul W. Zitzewitz
Publisher:Glencoe/McGraw-Hill
University Physics Volume 3
Physics
ISBN:9781938168185
Author:William Moebs, Jeff Sanny
Publisher:OpenStax
College Physics
Physics
ISBN:9781938168000
Author:Paul Peter Urone, Roger Hinrichs
Publisher:OpenStax College
Modern Physics
Physics
ISBN:9781111794378
Author:Raymond A. Serway, Clement J. Moses, Curt A. Moyer
Publisher:Cengage Learning