Concept explainers
BIO Amazing honeybees The survival of a bee colony depends on the ability of bee scouts to locate food and to convey that information to the hive. After finding a promising food source, a honeybee scout returns to the hive and uses a waggle dance to tell its worker sisters the direction and distance to the food.
Recall that light coming directly from the Sun is unpolarized Bees use the direction of the Sun as a reference for their travel In the hive, the scout bee's waggle dance is in the shape of a flat figure eight (Figure 25.28). The upward direction in the vertical hive represents the direction toward the Sun. The middle line of the scout’s figure eight points in the direction of the food relative to the direction of the Sun. Thus a
Incandescent lightbulbs—soon to disappear Australia, Canada, New Zealand, and the European Union started phasing out incandescent lightbulbs in 2009. The United States phased them out in 2014. These bulbs have provided light for the world for more than 90 years What’s the problem?
Incandescent lightbulbs produce light when electrons (
Banning incandescent bulbs will reduce energy usage According to the Department of Energy, about
What is the rate of visible light emission from a 100-W incandescent lightbulb?
a. 10 W
b. 20 W
c. 50 W
d. 100 W
e. Not enough information to make a determination
Want to see the full answer?
Check out a sample textbook solutionChapter 25 Solutions
Pearson eText for College Physics: Explore and Apply -- Instant Access (Pearson+)
Additional Science Textbook Solutions
University Physics Volume 2
Conceptual Integrated Science
The Cosmic Perspective Fundamentals (2nd Edition)
University Physics Volume 1
College Physics: A Strategic Approach (4th Edition)
Physics (5th Edition)
- You are working for SETI, the Search for Extraterrestrial Intelligence. One day, you receive a radio communication from an alien intelligence. Although you cannot understand their language, they have included some photos from an I Love Lucy episode. The photos allow you to determine that it is the episode in which Lucy makes a television commercial on Vitameatavegamin. This episode first aired on CBS on May 5, 1952. Before running to your supervisor to tell him the news, you quickly determine how far away in light-years the alien civilization is.arrow_forwardLunar astronauts placed a reflector on the Moon's Surface, off which a laser beam is periodically reflected. The distance to the Moon is calculated from the round-trip time. (a) To what accuracy in meters can the distance to the Moon be determined, if this time can be measured to 0.100 ns? (b) What percent accuracy is this, given the average distance to the Moon is 3.84108m ?arrow_forwardThe Tunguska event. On June 30, 1908, a meteor burned up and exploded in the atmosphere above the Tunguska River valley in Siberia. It knocked down trees over thousands of square kilometers and started a forest fire, but produced no crater and apparently caused no human casualties. A witness sitting on his doorstep outside the zone of falling trees recalled events in the following sequence. He saw a moving light in the sky, brighter than the Sun and descending at a low angle to the horizon. He felt his face become warm. He felt the ground shake. An invisible agent picked him up and immediately dropped him about a meter from where he had been seated. He heard a very loud protracted rumbling. Suggest an explanation for these observations and for the order in which they happened.arrow_forward
- A distant astronomical object (a quasar) is moving away from us at half the speed of light. What is the speed of the light we receive from this quasar? (a) greater than c (b) c (c) between c/2 and c (d) c/2 (e) between 0 and c/2arrow_forwardAn interstellar space probe is launched from Earth. After a brief period of acceleration, it moves with a constant velocity, 70.0% of the speed of light. Its nuclear-powered batteries supply the energy to keep its data transmitter active continuously. The batteries have a lifetime of 15.0 years as mean red in a rest frame. (a) How long do the batteries on the space probe last as measured by mission control on Earth? (b) How far is the probe from Earth when its batteries fail as measured by mission control? (c) How far is the probe from Earth as measured by its built-in trip odometer when its batteries fail? (d) For what total time after launch are data received from the probe by mission control? Note that radio waves travel at the speed of light and till the space between the probe and Earth at the time the battery fails.arrow_forwardThe motion of a transparent medium influences the speed of light. This effect was first observed by Fizeau in 1851. Consider a light beam in water. The water moves with speed v in a horizontal pipe. Assume the light travels in the same direction as the water moves. The speed of light with respect to the water is c/n. where n = 1.33 is the index of refraction of water. (a) Use the velocity transformation equation to show that the speed of the light measured in the laboratory frame is u=cn(1+nv/c1+v/nc) (b) Show that for v c, the expression from part (a) becomes, to a good approximation, u=cn+vvn2 (c) Argue for or against the view that we should expect the result to be u = (c/n) + v according to the Galilean transformation and that the presence of the term v/n2 represents a relativistic effect appearing even at nonrelativistic speeds. (d) Evaluate u in the limit as the speed of the water approaches c.arrow_forward
- Near the center of our galaxy, hydrogen gas is moving directly away from us in its orbit about a black hole. We receive 1900 nm electromagnetic radiation and know that it was 1875 nm when emitted by the hydrogen gas. What is the speed of the gas?arrow_forwardThe constant speed at which light and other forms of radiation travel is:A. 186 X 105 meters/sec.B. 4.29 X 1014 meters/sec.C. 3.00 X 108 meters/sec.D. 5.45 X 1014 meters/sec.Reset SelectionMark for Review What’s This?arrow_forward6. Light sensors are widely used in energy-efficient lighting control. List the three major types of light sensors and briefly describe how they each proportionally convert the change of the light intensity to change in an electrical signal.arrow_forward
- Which of the following is not a scalar field? a. Temperature distribution in your classroom b. Atmospheric pressure in a given region c. Light intensity in a drawing room d. Displacement of a mosquito in spacearrow_forwardThe main difference between a radio wave and a light wave is its Select one: a. speed. b. wavelength. c. speed and wavelength d. none of the above.arrow_forwardunited4 EM Waves Infrared waves from the sun are what make our skin feel warm on a sunny day. If an infrared wave has a frequency of 3.0 x 1012 Hz, what is its wavelength? O 1.0x 10 4 m O 10,000 m O 3.3 x10-133 O 9.0 x 1020 m 1 2 3 4 5 6 7 8 9 10 /united4sisd.schoology.com/common-assessment-delveny/start/47261130007actions onresume&submissionld=437401404 Type here to searcharrow_forward
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
- Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning