Modern Physics
3rd Edition
ISBN: 9781111794378
Author: Raymond A. Serway, Clement J. Moses, Curt A. Moyer
Publisher: Cengage Learning
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Chapter 1, Problem 15P
The classical Doppler shift for light. A light source recedes from an observer with a speed v that is small compared with c. (a) Show that in this case, Equation 1.15 reduces to
(b) Also show that in this case
(Hint: Differentiate λf = c to show that Δλ/λ = –Δf/f) (c) Spectroscopic measurements of an absorption line normally found at λ = 397 nm reveal a redshift of 20 nm for light coming from a galaxy in Ursa Major. What is the recessional speed of this galaxy?
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A particle has γ=18,399.
a) Calculate c-v in m/s. (I would have asked for 1 - v/c, making the answer dimensionless, but the system doesn't seem to take numbers that small. Gamma is chosen to make the particle extremely close to the speed of light.)
If your calculator gives problems, you might want to solve the appropriate equation for c-v or c(1 - v/c) and use an approximation.
b) In a race to the moon, by 3/4ths the distance, light is one or ten meters ahead of the particle. We routinely approximate mass as zero, gamma as infinite, and speed as the speed of light. ("Massless particles" -- gamma and m have to be eliminated from the expressions. Light is a true massless particle.)
If a massless particle has momentum 1,739 MeV/c, calculate its energy in MeV.
Thank you so much!!
A particle has γ=18,399.
a)Calculate c-v in m/s. (I would have asked for 1 - v/c, making the answer dimensionless, but the system doesn't seem to take numbers that small. Gamma is chosen to make the particle extremely close to the speed of light.)
If your calculator gives problems, you might want to solve the appropriate equation for c-v or c(1 - v/c) and use an approximation.
b) In the previous problem, in a race to the moon, by 3/4ths the distance, light is one or ten meters ahead of the particle. We routinely approximate mass as zero, gamma as infinite, and speed as the speed of light. ("Massless particles" -- gamma and m have to be eliminated from the expressions. Light is a true massless particle.) If a massless particle has momentum 1,739 MeV/c, calculate its energy in MeV.
Problem 2.
Prove that if the relative velocity of the transmitter
toward the receiver is +v m/sec, the received frequency of the RF carrier at
fe Hz is given by
fr
=
(1+v/c) fe
√1-(v/c)2
and if the relative velocity of the transmitter away the receiver is -v m/sec,
the received frequency of the RF carrier at fc Hz is given by
where c is the speed of light.
Hint: Use special relativity.
(1-v/c)fe
fr
=
√1-(v/c)2
Chapter 1 Solutions
Modern Physics
Ch. 1.2 - Prob. 1ECh. 1.2 - Exercise 2 Conservation of Linear Momentum Is...Ch. 1.5 - If the speed of the observer is increased by 5.0%,...Ch. 1.5 - If the ship moves past the observer at 0.01000c,...Ch. 1.6 - Prob. 5ECh. 1 - What two measurements will two observers in...Ch. 1 - A spaceship in the shape of a sphere moves past an...Ch. 1 - An astronaut moves away from Earth at a speed...Ch. 1 - Two identically constructed clocks are...Ch. 1 - Two lasers situated on a moving spacecraft are...
Ch. 1 - Prob. 6QCh. 1 - When we speak of time dilation, do we mean that...Ch. 1 - Prob. 8QCh. 1 - Prob. 9QCh. 1 - It is said that Einstein, in his teenage years,...Ch. 1 - Prob. 11QCh. 1 - What happens to the density of an object as its...Ch. 1 - In a lab frame of reference, an observer finds...Ch. 1 - Prob. 2PCh. 1 - Prob. 3PCh. 1 - An airplane flying upwind, downwind, and crosswind...Ch. 1 - Prob. 5PCh. 1 - Prob. 6PCh. 1 - A clock on a moving spacecraft runs 1 s slower per...Ch. 1 - A meter stick moving in a direction parallel to...Ch. 1 - A spacecraft moves at a speed of 0.900c. If its...Ch. 1 - The average lifetime of a pi meson in its own...Ch. 1 - An atomic clock is placed in a jet airplane. The...Ch. 1 - An astronaut at rest on Earth has a heartbeat rate...Ch. 1 - The muon is an unstable particle that...Ch. 1 - A rod of length L0 moves with a speed v along the...Ch. 1 - The classical Doppler shift for light. A light...Ch. 1 - Calculate, for the judge, how fast you were going...Ch. 1 - Prob. 17PCh. 1 - Prob. 18PCh. 1 - Two spaceships approach each other, each moving...Ch. 1 - Prob. 20PCh. 1 - An observer on Earth observes two spacecraft...Ch. 1 - Speed of light in a moving medium. The motion of a...Ch. 1 - An observer in frame S sees lightning...Ch. 1 - As seen from Earth, two spaceships A and B are...Ch. 1 - Prob. 25PCh. 1 - The proper length of one spaceship is three times...Ch. 1 - Prob. 27PCh. 1 - Prob. 28PCh. 1 - A spaceship moves away from Earth at a speed v and...Ch. 1 - An observer in a rocket moves toward a mirror at...Ch. 1 - A physics professor on Earth gives an exam to her...Ch. 1 - A yet-to-be-built spacecraft starts from Earth...Ch. 1 - Suppose our Sun is about to explode. In an effort...Ch. 1 - Two powerless rockets are on a collision course....Ch. 1 - Prob. 35PCh. 1 - Suzanne observes two light pulses to be emitted...Ch. 1 - An observer in reference frame S sees two events...Ch. 1 - A spacecraft is launched from the surface of the...Ch. 1 - An Earth satellite used in the Global Positioning...Ch. 1 - Prob. 40P
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