Question

Ignore air resiststance and Gravity.

1. When Hydrogen is heated on earth, it emits 4 colours of visible light of wavelengths 410 nm, 434 nm, 486 nm and 656 nm. When Hydrogen on a distant galaxy is observed, the 410 nm light appears to have a wavelength of 409 nm.

a) Is the galaxy moving towards earth or away from it? Explain.

b) Find the relative velocity of the galaxy with respect to the observer on earth. [Note: For this question, maintain a lot of accuracy by carrying a lot of digits in your calculations.]

c) Find the observed wavelengths of these other wavelengths of light originating from that galaxy.

Answer 1