Learning Materials
Features
Discover
Chapter 36: Q. 21 (page 1059)
At what speed, as a fraction of , will a moving rod have a length that of an identical rod at rest?
The speed is.
Over 30 million students worldwide already upgrade their learning with 91影视!
All the tools & learning materials you need for study success - in one app.
Get started for free
Teenagers Sam and Tom are playing chicken in their rockets. As FIGURE Q36.2 shows, an experimenter on earth sees that each is traveling at as he approaches the other. Sam fires a laser beam toward Tom.
a. What is the speed of the laser beam relative to Sam?
b. What is the speed of the laser beam relative to Tom?
This chapter has assumed that lengths perpendicular to the direction of motion are not affected by the motion. That is, motion in the -direction does not cause length contraction along the or axes. To find out if this is really true, consider two spray-paint nozzles attached to rods perpendicular to the axis. It has been confirmed that, when both rods are at rest, both nozzles are exactly 1 m above the base of the rod. One rod is placed in the reference frame with its base on the axis; the other is placed in the reference frame with its base on the axis. The rods then swoop past each other and, as FIGURE P36.60 shows, each paints a stripe across the other rod.
We will use proof by contradiction. Assume that objects perpendicular to the motion are contracted. An experimenter in frame finds that the nozzle, as it goes past, is less than above the axis. The principle of relativity says that an experiment carried out in two different inertial reference frames will have the same outcome in both.
a. Pursue this line of reasoning and show that you end up with a logical contradiction, two mutually incompatible situations.
b. What can you conclude from this contradiction?
A rocket fires a projectile at a speed of while traveling past the earth. Does an earthbound scientist measure the projectile鈥檚 speed to be What was the rocket鈥檚 speed as a fraction of ?
On a futuristic highway, a long rocket travels so fast that a red stoplight, with a wavelength of , appears to the pilot to be a green light with a wavelength of . What is the length of the rocket to an observer standing at the intersection as the rocket speeds through?
What is the speed, as a fraction of , of a particle whose momentum is ?
What do you think about this solution?
We value your feedback to improve our textbook solutions.
Explanations 
Textbooks 
Flashcards 
91影视 AI 
Notes 
Study Plans 
Study Sets 
Find a degree 
Magazine