Electrons - Relativistic velocity addition

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Homework Help Overview

The discussion revolves around the relativistic velocity addition of two electrons, each measured at a speed of c/2 in perpendicular directions (one in the x direction and the other in the y direction). Participants are exploring how to correctly calculate the relative speed of these electrons using principles of special relativity.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • One participant attempts to calculate the relative speed using a non-relativistic approach, questioning whether their method is appropriate given the high velocities involved. Others point out the necessity of using relativistic velocity addition instead.

Discussion Status

The discussion is ongoing, with participants recognizing the need to apply special relativity to the problem. Some guidance has been offered regarding the inadequacy of non-relativistic methods for this scenario, but no consensus or resolution has been reached.

Contextual Notes

Participants are grappling with the implications of relativistic speeds and the appropriate mathematical framework to apply, indicating a potential gap in understanding the differences between classical and relativistic velocity addition.

charmedbeauty
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electrons -- Relativistic velocity addition...

Homework Statement



an observer measures the velocity of two electrons, finding one with a speed c/2 in the x direction and the other c/2 in the y direction. what is the relative speed of the two electrons.



Homework Equations





The Attempt at a Solution



Im not sure if this is right it seemed to easy.

but suppose that electron 1 is called b and the other a

then v(b)= √(c2/4+c2/4)
since they are at right angles to each other. is this right?
 
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The velocities are very high, you need to use special relativity here.
 


charmedbeauty said:

Homework Statement



an observer measures the velocity of two electrons, finding one with a speed c/2 in the x direction and the other c/2 in the y direction. what is the relative speed of the two electrons.



Homework Equations





The Attempt at a Solution



Im not sure if this is right it seemed to easy.

but suppose that electron 1 is called b and the other a

then v(b)= √(c2/4+c2/4)
since they are at right angles to each other. is this right?

No. That is a non-relativistic velocity-addition and would give you the right answer for a speeding bullet on Earth but NOT for things traveling at relativistic speeds.

Google relativistic velocity addition
 


voko said:
The velocities are very high, you need to use special relativity here.

phinds said:
No. That is a non-relativistic velocity-addition and would give you the right answer for a speeding bullet on Earth but NOT for things traveling at relativistic speeds.

Google relativistic velocity addition

oh yeah that makes sense ok cool thanks.
 


How did you go with the rest of the assignment =P
 

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