Suppose the
Explain the consequences of a light speed of 30ms-1 on our everyday life.
Answer to Problem 1CQ
Slowing down the speed of light to 30 ms-1 makes apparent changes in length, time and color observed by an observer.
Explanation of Solution
Write the expression for length contraction,
Where,
Here,
In this case,
As
If a person moving with a velocity
Write the expression for time dilation,
Here,
Since the object is considered to be at rest in S´ frame, time observed in this frame is considered proper time.
As
Thus a person moving with a velocity
Write the expression for Doppler effect when the source is approaching
Where,
Write the expression for Doppler effect when the source is receding,
Here,
As
Want to see more full solutions like this?
Chapter 27 Solutions
College Physics (10th Edition)
Additional Science Textbook Solutions
Modern Physics
Tutorials in Introductory Physics
University Physics (14th Edition)
An Introduction to Thermal Physics
Glencoe Physical Science 2012 Student Edition (Glencoe Science) (McGraw-Hill Education)
Life in the Universe (4th Edition)
- A physics professor on the Earth gives an exam to her students, who are in a spacecraft traveling at speed v relative to the Earth. The moment the craft passes the professor, she signals the start of the exam. She wishes her students to have a time interval T0 (spacecraft time) to complete the exam. Show that she should wait a time interval (Earth time) of T=T01/c1+/c before sending a light signal telling them to stop. (Suggestion: Remember that it takes some time for the second light signal to travel from the professor to the students.)arrow_forwardIf you use an Earth-based telescope to project a laser beam onto the Moon, you can move the spot across the Moon's surface at a velocity greater than the speed of light. Does this Violate modern relativity? (Note that light is being sent from the Earth to the Moon, not across the surface of the Moon.)arrow_forwardYou are driving on a freeway at a relativistic speed. Straight ahead of you, a technician standing on the ground turns on a searchlight and a beam of light moves exactly vertically upward, as seen by the technician. As you observe the beam of light, you measure the magnitude of the vertical component of its velocity as (a) equal to c, (b) greater than c, or (c) less than c. If the technician aims the searchlight directly at you instead of upward, you measure the magnitude of the horizontal component of its velocity as (d) equal to c, (e) greater than c, or (f) less than c.arrow_forward
- A spaceship moves past Earth with a speed of 0.900c. As it is passing, a person on Earth measures the spaceship's length to be 75.0 m. (a) Determine the spaceships proper length. (b) Determine the time required for the spaceship to pass a point on Earth as measured by a person on Earth and (c) by an astronaut onboard the spaceship.arrow_forwardA spaceship moves past Earth with a speed of 0.900c. As it is passing, a person on Earth measures the spaceship's length to be 75.0 m. (a) Determine the spaceships proper length. (b) Determine the time required for the spaceship to pass a point on Earth as measured by a person on Earth and (c) by an astronaut onboard the spaceship.arrow_forwardReview. A global positioning system (GPS) satellite moves in a circular orbit with period 11 h 58 min. (a) Determine the radius of its orbit. (b) Determine its speed. (c) The nonmilitary GPS signal is broadcast at a frequency of 1 575.42 MHz in the reference frame of the satellite. When it is received on the Earths surface by a GPS receiver (Fig. P38.41), what is the fractional change in this frequency due to time dilation as described by special relativity? (d) The gravitational blueshift of the frequency according to general relativity is a separate effect. It is called a blueshift to indicate a change to a higher frequency. The magnitude of that fractional change is given by ff=Ugmc2 where Ug is the change in gravitational potential energy of an objectEarth system when the object of mass m is moved between the two points where the signal is observed. Calculate this fractional change in frequency due to the change in position of the satellite from the Earths surface to its orbital position. (e) What is the overall fractional change in frequency due to both time dilation and gravitational blueshift? Figure P38.41arrow_forward
- An astronaut moves away from Earth at a speed close to the speed of light. If an observer on Earth could make measurements of the astronauts size and pulse rate, what changes (if any) would he or she measure? Would the astronaut measure any changes?arrow_forwardAn alarm clock is set to sound in 10.0 h. At t = 0, the clock is placed in a spaceship moving with a speed of 0.75c (relative to Earth). What distance, as determined by an Earth observer, does the spaceship travel before the alarm clock sounds?arrow_forwardSpeed of light in a moving medium. The motion of a medium such as water influences the speed of light. This effect was first observed by Fizeau in 1851. Consider a light beam passing through a horizontal column of water moving with a speed v. (a) Show that if the beam travels in the same direction as the flow of water, the speed of light measured in the laboratory frame is given by where n is the index of refraction of the water. (Hint: Use the inverse Lorentz velocity transformation and note that the speed of light with respect to the moving frame is given by c/n.) (b) Show that for v << c, the preceding expression is in good agreement with Fizeau’s experimental result: This proves that the Lorentz velocity transformation and not the Galilean velocity transformation is correct for light.arrow_forward
- Derive the equation p = 0.3Br using the concepts of centripetal acceleration (Motion in TWO and Three Dimensions (http://cnx.org/content/m58288/ latest/)) and relativistic momentum (Relativity)arrow_forward(a) Suppose the speed of light were only 3000 m/s. A jet fighter moving toward a target on the ground at 800 m/s shoots bullets, each having a muzzle velocity of 1000 m/s. What are the bullets' velocity relative to the target? (b) If the speed of light was this small, would you observe relativistic effects in everyday life? Discuss.arrow_forwardA friend passes by you in a spacecraft traveling at a high speed. He tells you that his craft is 20.0 m long and that the identically constructed craft you are sitting in is 19.0 m long. According to your observations, (a) how long is your spacecraft, (b) how long is your friends craft, and (c) what is the speed of your friends craft?arrow_forward
- College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegeModern PhysicsPhysicsISBN:9781111794378Author:Raymond A. Serway, Clement J. Moses, Curt A. MoyerPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning