Applied Physics (11th Edition)
11th Edition
ISBN: 9780134159386
Author: Dale Ewen, Neill Schurter, Erik Gundersen
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Textbook Question
Chapter 20.5, Problem 15P
If an observer triples her distance from a light source: (a) Does the illumination at that point increase or decrease? (b) In what proportion does the illumination increase or decrease?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
(a) The distance to a star is approximately 4.97 × 10¹8 m. If this star were to burn out today, in how many years would we see it disappear?
years
(b) How long does it take sunlight to reach Earth?
minutes
(c) How long does it take for a microwave radar signal to travel from Earth to the Moon and back? (The distance from Earth to the Moon is 3.84 x 105 km.)
S
How long will it take, for the sunlight to reach the
earth surface, if the sun is 1.497 x 10"m away from
the earth? (Consider the speed of light in vacuum)
When the sun is either rising or setting and appears to be just on the horizon, it is in fact below the horizon. The explanation for this seeming paradox is that light from the sun bends slightly when entering the earth’s atmosphere, as shown in Fig. Since our perception is based on the idea that light travels in straight lines, we perceive the light to be coming from an apparent position that is an angle d above the sun’s true position. (a) Make the simplifying assumptions that the atmosphere has uniform density, and hence uniform index of refraction n, and extends to a height h above the earth’s surface, at which point it abruptly stops. Show that the angle d is given by as attached. where R = 6378 km is the radius of the earth. (b) Calculate d using n = 1.0003 and h = 20 km. How does this compare to the angular radius of the sun, which is about one quarter of a degree? (In actuality a light ray from the sun bends gradually, not abruptly, since the density and refractive index of the…
Chapter 20 Solutions
Applied Physics (11th Edition)
Ch. 20.2 - Find the distance (in metres) traveled by a radio...Ch. 20.2 - Prob. 2PCh. 20.2 - A television signal is sent to a communications...Ch. 20.2 - How long does it take for a radio signal from the...Ch. 20.2 - The sun is 9.30107mi from the earth. How long does...Ch. 20.2 - A radar wave is bounced off an airplane and...Ch. 20.2 - How long does it take for a radio wave to travel...Ch. 20.2 - How long does it take for a flash of light to...Ch. 20.2 - How long does it take for a police radar beam to...Ch. 20.2 - How far away (in km) is an airplane if the radar...
Ch. 20.2 - An auto mechanic uses a strobe light to time a...Ch. 20.2 - A construction company uses GPS technology to...Ch. 20.2 - (a) How long does it take for light to reach the...Ch. 20.2 - Prob. 14PCh. 20.2 - How long does it take light to reach the earth...Ch. 20.2 - Preparing for reentry, astronauts use radar to...Ch. 20.2 - Prob. 17PCh. 20.2 - Light from the sun travels 1.50108 km to reach the...Ch. 20.3 - c=3.00108m/s =4.55105m f=?Ch. 20.3 - c=3.00108m/s =9.701010m f=?Ch. 20.3 - c=3.00108m/s f=9.701011Hz =?Ch. 20.3 - c=3.00108m/s f=24.2 MHz =?Ch. 20.3 - c=3.00108m/s f=45.6 MHz =?Ch. 20.3 - Prob. 6PCh. 20.3 - Prob. 7PCh. 20.3 - Prob. 8PCh. 20.3 - Find the wavelength of a radio wave from an AM...Ch. 20.3 - Find the wavelength of a radio wave from an FM...Ch. 20.3 - Find the frequency of an electromagnetic wave if...Ch. 20.3 - Find the frequency of an electromagnetic wave if...Ch. 20.3 - Prob. 13PCh. 20.3 - Prob. 14PCh. 20.3 - Prob. 15PCh. 20.3 - An AM radio station broadcasts a signal with a...Ch. 20.4 - Prob. 1PCh. 20.4 - Prob. 2PCh. 20.4 - Prob. 3PCh. 20.4 - Find the frequency of electromagnetic radiation...Ch. 20.4 - Find the frequency of electromagnetic radiation...Ch. 20.4 - Prob. 6PCh. 20.4 - Find the frequency of electromagnetic radiation...Ch. 20.4 - Prob. 8PCh. 20.4 - Prob. 9PCh. 20.4 - Prob. 10PCh. 20.4 - Prob. 11PCh. 20.4 - Prob. 12PCh. 20.4 - An AM radio station in a nearby town broadcasts a...Ch. 20.5 - I=48.0 cd I=___mCh. 20.5 - Prob. 2PCh. 20.5 - I=765 m I=___ cdCh. 20.5 - I=432 m I=___ cdCh. 20.5 - I=75.0 cd I=___ mCh. 20.5 - I=650 m I=___ cdCh. 20.5 - I=900 m r=7.00 ft E=?Ch. 20.5 - I=741 m r=6.50 m E=?Ch. 20.5 - I=893 m r=3.25 ft E=?Ch. 20.5 - E=4.32 lux r=9.00 m I=?Ch. 20.5 - E=10.5 ft-candles r=6.00 ft I=?Ch. 20.5 - Prob. 12PCh. 20.5 - Prob. 13PCh. 20.5 - Prob. 14PCh. 20.5 - If an observer triples her distance from a light...Ch. 20.5 - If the illuminated surface is slanted at an angle...Ch. 20.5 - Find the illumination on a surface by three light...Ch. 20.5 - Find the intensity of two identical light sources...Ch. 20.5 - Find the intensity of two identical light sources...Ch. 20.5 - A desk is 3.35 m below an 1850-m incandescent...Ch. 20 - Which of the following are examples of...Ch. 20 - Prob. 2RQCh. 20 - Prob. 3RQCh. 20 - Light behaves a. as a massive particle. b. always...Ch. 20 - Does the wavelength of light depend on its...Ch. 20 - Prob. 6RQCh. 20 - How does the intensity of illumination depend on...Ch. 20 - In your own words, explain how the speed of light...Ch. 20 - Does light always travel at the same speed?...Ch. 20 - What name is given to the entire range of waves...Ch. 20 - Prob. 11RQCh. 20 - Who developed the wave packet theory of light?Ch. 20 - Who made the first estimate of the speed of light?Ch. 20 - How was the first estimate of the speed of light...Ch. 20 - What are the units of luminous intensity?Ch. 20 - In your own words, explain luminous intensity.Ch. 20 - Find the distance (in metres) traveled by a radio...Ch. 20 - A radar wave that is bounced off an airplane...Ch. 20 - How long does it take for a police radar beam to...Ch. 20 - Prob. 4RPCh. 20 - How long does it take for a radio signal to travel...Ch. 20 - Find the wavelength of a radio wave from an AM...Ch. 20 - Find the frequency of a radio wave if its...Ch. 20 - Prob. 8RPCh. 20 - Prob. 9RPCh. 20 - Prob. 10RPCh. 20 - Prob. 11RPCh. 20 - Prob. 12RPCh. 20 - Prob. 13RPCh. 20 - Find the intensity of the light source necessary...Ch. 20 - Prob. 15RPCh. 20 - Find the intensity of two identical light sources...Ch. 20 - Find the illumination on a surface by three light...Ch. 20 - Prob. 1ACCh. 20 - (a) When the Apollo astronauts landed on the moon,...Ch. 20 - Prob. 3ACCh. 20 - The individual rods on rooftop antennas are...Ch. 20 - Prob. 5AC
Additional Science Textbook Solutions
Find more solutions based on key concepts
Description of Motion:
Tutorials in Introductory Physics
3. What is free-fall, and why does it make you weightless? Briefly describe why astronauts are weightless in th...
The Cosmic Perspective
Suppose you are doing a physics lab that asks you to put a resistor into a circuit, but all the resistors suppl...
University Physics Volume 2
The pV-diagram of the Carnot cycle.
Sears And Zemansky's University Physics With Modern Physics
6. State Newton's second law.
Conceptual Physical Science (6th Edition)
3. What is free-fall, and why does it make you weightless? Briefly describe why astronauts are weightless in th...
The Cosmic Perspective (8th Edition)
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
- In the figure, light from ray A refracts from material 1 (n₁ = 1.73) into a thin layer of material 2 (n2 = 1.80), crosses that layer, and is then incident at the critical angle on the interface between materials 2 and 3 (n3 = 1.40). (a) What is the value of incident angle BA? (b) If 8A is decreased, does part of the light refract into material 3? Light from ray B refracts from material 1 into the thin layer, crosses that layer, and is then incident at the critical angle on the interface between materials 2 and 3. (c) What is the value of incident angle Og? (d) If Og is decreased, does part of the light refract into material 3? OB I ng no 121arrow_forward(a) How long in seconds does it take a radio signal to travel 180 km from a transmitter to a receiving antenna? (b) We see a full Moon by reflected sunlight. How much earlier did the light that enters our eye leave the Sun? The Earth - Moon and Earth - Sun distances are 3.8x105 km and 1.5 x 108 km, respectively. (c) What is the round-trip travel time in seconds for light between Earth and a spaceship at a 9.0 x 106 km distance from Earth? (d) Suppose astronomers observe a supernova about 7600 light-years (ly) distant. How long ago in years did the explosion actually occur? (a) Number Units (b) Number Units (c) Number Units (d) Number Unitsarrow_forwardThe speed of light in any transparent medium is the same as the speed of light in a vacuum. true or false?arrow_forward
- (a) In the figure, light from ray A refracts from material 1 into a thin layer of material 2, crosses that layer, and is then incident at the critical angle on the interface between materials 2 and 3. (i) What is the value of incident angle θA? Draw a sketch of the situation. (ii) If θA is decreased, does part of the light refract into material 3? (b) Light from ray B refracts from material 1 into the thin layer, crosses that layer, and is then incident at the critical angle on the interface between materials 2 and 3. (iii) What is the value of incident angle θB? Draw a sketch of the situation. (iv) If θB is decreased, does part of the light refract into material 3? Answer: 54.3°, yes, 51.1°, noarrow_forward(a) The distance to a star is approximately 5.50 × 10¹8 m. If this star were to burn out today, in how many years would we see it disappear? 581.35 years (b) How long does it take sunlight to reach Earth? 8.33 minutes (c) How long does it take for a microwave radar signal to travel from Earth to the Moon and back? (The distance from Earth to the Moon is 3.84 x 105 km.) X 1.28 Your response differs from the correct answer by more than 10%. Double check your calculations. Sarrow_forwardHow far does light travel in one year? [This distance is known as a light-year (ly) and is used in measuring astronomical distances.] I think the answer might have to be in scientific notationn formarrow_forward
- The intensity of light I through a lake at a depth of x meters is given by the following formula. dI/dx = (-2.31)I a.) At what depth is the intensity of the light half that of the intensity at the surface, I00? b.) At 5 meters deep, what is the intensity of the light as a fraction of I0? c.) How many meters deep will the intensity of light be 1 percent of the intensity of the light at the surface? Remember that the depth at the surface is x = 0.arrow_forwardYou are a detective interviewing someone who says that (while sitting on a porch that you know to be 600ft away) he saw the masked suspect commit the crime in broad daylight. "How do you know it was the suspect?" you ask. "I clearly saw the 'MOM' that is tattooed on his upper arm." "You're sure it was that particular tattoo and not some other tattoo?" "Yes, I'm sure," The witness replies. The suspect's tattoo has letters that are 6cm tall. Is the witness credible, or might he be framing the suspect? Justify your response and any estimates you might make.arrow_forwardIf JÃ+ë |= |à | = |6|, then the angle between à and é is (d) 120° (а) 0° (b) 60° (c) 90° aswer: (d)arrow_forward
- Distances in space are often quoted in units of light years, the distance light travels in one year. (a) How many meters is a light year? m (b) How many meters is it to Andromeda, the nearest large galaxy, given that it is 2.00 ✕ 106 light years away? m (c) The most distant galaxy yet discovered is 12.0 ✕ 109 light years away. How far is this in meters? marrow_forwardThe wavelength of light is 5000 A. Find the wave number. (a) 0 5x 10 (b) 3x 10° (c) 2x10 (d) 1x 10°arrow_forwardA beam of light is directed toward the surface of a block of fused quartz at an angle of 28.0° with respect to the normal (a line perpendicular to the surface at the spot where the ray hits the block). A fraction of the light is reflected and the rest refracted. What is the angle (in degrees) between the reflected and refracted beams?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningUniversity Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSONIntroduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningLecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-WesleyCollege Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
University Physics (14th Edition)
Physics
ISBN:9780133969290
Author:Hugh D. Young, Roger A. Freedman
Publisher:PEARSON
Introduction To Quantum Mechanics
Physics
ISBN:9781107189638
Author:Griffiths, David J., Schroeter, Darrell F.
Publisher:Cambridge University Press
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:9780321820464
Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:Addison-Wesley
College Physics: A Strategic Approach (4th Editio...
Physics
ISBN:9780134609034
Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:PEARSON
Polarization of Light: circularly polarized, linearly polarized, unpolarized light.; Author: Physics Videos by Eugene Khutoryansky;https://www.youtube.com/watch?v=8YkfEft4p-w;License: Standard YouTube License, CC-BY