Homework Statement
In a distant galaxy, an emission line of hydrogen that has a rest wavelength of 656 nm has an observed wavelength of 662.6 nm. Is the galaxy moving away from us or toward us? How fast is it moving in (km/sec)?
Homework Equations
velocity = ((shifted wavelength -...
I apologize for suggesting that your reply was an opinion. I used your reasoning to arrive at an answer that I understand and am satisfied with. Thanks for your help.
(0.8c - 0.5c) / (1 + (0.8c/c)(-0.5c/c)) = 0.5c
Any other opinions? I'm wondering now if it would just be as simple as 0.8c - 0.5c = 0.3c, since the velocity-addition formula is usually used if there is a third stationary object observing the other two objects in motion, and there is no third object in this problem.
Homework Statement
Two spaceships are traveling on the interstellar freeway. Ship A is traveling at 0.5 c and Ship B is traveling at 0.8 c. Ship B passes Ship A. How fast does the pilot of Ship A see Ship B moving away from her? (c is speed of light)Homework Equations
I think the...