Relative Velocities

  • Thread starter Quarlep
  • Start date
  • #1
257
4
Lets suppose three objects O,A and B are set up in universe and nothing else.Then O seems A is moving 0.3c And B is moving 0.5c .In Special Relativity we have relative velocities formula I want to formule it but result seems absurd can you find me all possible velocities I mean A, O and B observer
Thank you
 

Answers and Replies

  • #2
Doc Al
Mentor
45,033
1,335
In Special Relativity we have relative velocities formula I want to formule it but result seems absurd
What results did you get? Why do they seem absurd?
 
  • #3
257
4
VCB=VOB-VOC I thought like this But this is not true in special relativity.In special Relativity it like the relative formule for special relativity isnt it ?
 
Last edited:
  • #4
Doc Al
Mentor
45,033
1,335
VCB=VOB-VOC
You'll need to define your terms. (What is C, for example?)

I thought like this But this is not true in special relativity.In special Relativity it like the relative formule for special relativity isnt it ?
You'll certainly need to add the velocities using special relativity, not Galilean relativity.
 
  • #5
257
4
C is speed to O
 
  • #6
DrGreg
Science Advisor
Gold Member
2,308
1,051
VCB=VOB-VOC
But you said there were only 3 objects O, A and B, so there is no object C? I'm going to assume by "C" you mean "A", so, in Newtonian theory it would be[tex]
v_{AB} = v_{OB} - v_{OA}.
[/tex]Then in special relativity it is[tex]
v_{AB} = \frac{ v_{OB} - v_{OA} } { 1 - \frac{ v_{OB} v_{OA} } {c^2} },
[/tex](provided all velocities are parallel).
 
  • #7
257
4
Thanks
 

Related Threads on Relative Velocities

  • Last Post
Replies
10
Views
1K
  • Last Post
Replies
1
Views
5K
  • Last Post
Replies
4
Views
843
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
19
Views
4K
  • Last Post
3
Replies
53
Views
3K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
15
Views
3K
Top