Velocity Addition: Consider Three Galaxies, Alpha, Beta and Gamma

question 45

Multiple Choice

Velocity addition: Consider three galaxies, Alpha, Beta and Gamma. An observer in Beta sees the other two galaxies each moving away from him in opposite directions at speed 0.70c. At what speed would an observer in Alpha see the galaxy Beta moving?

• A) 0.82c
• B) 0.70c
• C) 0.94c
• D) 0.35c
• E) 0.57c