# help please?

A galaxy ngc 4414 is moving awat from us at 7.16*10^5. by how much will the frequency of the 6.91*10^14 hz hydrogen line be shifted in the galaxy's spectrum?

### 1 Answer

Relevance

- NCSLv 75 months agoFavorite Answer
f = f₀ * c / (c + v)

where c is the speed of light and v is the speed of the galaxy moving away

so

f = 6.91e14Hz * 3e8 / (3e8 + 7.16e5) = 6.89e14 Hz

and so the SHIFT is

(6.91 - 6.89)e14 Hz = 1.65e12 Hz

Hope this helps!

Still have questions? Get answers by asking now.