University Physics with Modern Physics Plus Mastering Physics with eText -- Access Card Package (14th Edition)
14th Edition
ISBN: 9780321982582
Author: Hugh D. Young, Roger A. Freedman
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 38, Problem 38.7DQ
To determine
The reason for human skin being insensitive to visible light but severe burns are caused by ultraviolet
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Human skin is relatively insensitive to visible light, but ultraviolet radiation can cause severe burns. Does this have anything to do with photon energies? Explain.
a) Draw a graph that shows the relationship between the frequency of the incident radiation
and the maximum kinetic energy of the electrons emitted from the photoelectric surface.
Energy as a function of frequency:
F7
3.50-
3.00
250
2.a-
1.50
1.00
0.50 -
1.0
20 3.0 4.O 5.0 60 7.0
Frequency (xl04“ te)
b) Using your graph, determine the threshold frequency and Planck's Constant.
17
Planck's Consrant
Slope
erise
E
%3D
run
Energy (x10-193)
A certain helium-neon laser pointer, emitting light with a wavelength of 632 nm, has a beam with an intensity of 715 W/m2 and a diameter of 2.70 mm. How many photons are emitted by the laser pointer every second?
Thank you for the help!
Chapter 38 Solutions
University Physics with Modern Physics Plus Mastering Physics with eText -- Access Card Package (14th Edition)
Ch. 38.1 - Silicon films become better electrical conductors...Ch. 38.2 - Prob. 38.2TYUCh. 38.3 - Prob. 38.3TYUCh. 38.4 - Prob. 38.4TYUCh. 38 - Prob. 38.1DQCh. 38 - Prob. 38.2DQCh. 38 - Prob. 38.3DQCh. 38 - Prob. 38.4DQCh. 38 - Prob. 38.5DQCh. 38 - Prob. 38.6DQ
Ch. 38 - Prob. 38.7DQCh. 38 - Prob. 38.8DQCh. 38 - Prob. 38.9DQCh. 38 - Prob. 38.10DQCh. 38 - Prob. 38.11DQCh. 38 - Prob. 38.12DQCh. 38 - Prob. 38.13DQCh. 38 - Prob. 38.14DQCh. 38 - Prob. 38.15DQCh. 38 - Prob. 38.16DQCh. 38 - Prob. 38.17DQCh. 38 - Prob. 38.1ECh. 38 - Prob. 38.2ECh. 38 - Prob. 38.3ECh. 38 - Prob. 38.4ECh. 38 - Prob. 38.5ECh. 38 - Prob. 38.6ECh. 38 - Prob. 38.7ECh. 38 - Prob. 38.8ECh. 38 - Prob. 38.9ECh. 38 - Prob. 38.10ECh. 38 - Prob. 38.11ECh. 38 - Prob. 38.12ECh. 38 - Prob. 38.13ECh. 38 - Prob. 38.14ECh. 38 - Prob. 38.15ECh. 38 - Prob. 38.16ECh. 38 - Prob. 38.17ECh. 38 - Prob. 38.18ECh. 38 - Prob. 38.19ECh. 38 - Prob. 38.20ECh. 38 - Prob. 38.21ECh. 38 - An electron and a positron are moving toward each...Ch. 38 - Prob. 38.23ECh. 38 - Prob. 38.24ECh. 38 - Prob. 38.25ECh. 38 - Prob. 38.26PCh. 38 - Prob. 38.27PCh. 38 - Prob. 38.28PCh. 38 - Prob. 38.29PCh. 38 - Prob. 38.30PCh. 38 - Prob. 38.31PCh. 38 - Prob. 38.32PCh. 38 - Prob. 38.33PCh. 38 - Prob. 38.34PCh. 38 - Prob. 38.35PCh. 38 - Prob. 38.36PCh. 38 - Prob. 38.37PCh. 38 - Prob. 38.38PCh. 38 - Prob. 38.39PCh. 38 - Prob. 38.40CPCh. 38 - Prob. 38.41PPCh. 38 - Prob. 38.42PPCh. 38 - Prob. 38.43PPCh. 38 - Prob. 38.44PPCh. 38 - Prob. 38.45PP
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) If the power output of a 650-kHz radio station is 50.0 kW, how many photons per second are produced? (b) If the radio waves are broadcast uniformly in all directions, find the number of photons per second per square meter at a distance of 100 km. Assume no reflection from the ground or absorption by the air.arrow_forwardHow many x-ray photons per second are created by an x ray tube that produces a flux of x rays having a power of 1.00 W? Assume the average energy per photon is 75.0 keV.arrow_forward(a) What is the maximum energy in eV of photons produced in a CRT using a 25.0-kV accelerating potential, such as a color TV? (b) What is their frequency?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_forwardIntegrated Concepts A certain heat lamp emits 200 W of mostly IR radiation averaging 1500 nm in wavelength. (a) What is the average photon energy in joules? (b) How many of these photons are required to increase the temperature of a person's shoulder by 2.0°C, assuming the affected mass is 4.0 kg with a specific heat of 0.83kcal/kgC. Also assume no other significant heat transfer. (c) How long does this take?arrow_forward(a) Find the momentum of a 4.00-cm-wavelength microwave photon. (b) Discuss why you expect the answer to (a) to be very small.arrow_forward
- (a) How far away must you be from a 650-kHz radio station with power 50.0 kW for there to be only one photon per second per square meter? Assume no reflections or absorption, as if you were in deep outer space. (b) Discuss the implications for detecting intelligent life in other solar systems by detecting their radio broadcasts.arrow_forward(a) Find the energy in joules and eV of photons in radio waves from an FM station that has a 90.0-MHz broadcast frequency. (b) What does this imply about the number of photons per second that the radio station must broadcast?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
- A 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_forwardThe velocity of a proton emerging from a Van de Graaff accelerator is 25.0% of the speed of light. (a) What is the proton's wavelength? (b) What is its kinetic energy, assuming it is nonrelativistic? (c) What was the equivalent voltage through which it was accelerated?arrow_forwardExposure 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.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 Learning
Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill
University Physics Volume 3PhysicsISBN:9781938168185Author:William Moebs, Jeff SannyPublisher:OpenStax
College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College
Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher: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
Physics for Scientists and Engineers with Modern ...
Physics
ISBN:9781337553292
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning