A hydrogen line in a star's spectrum has a frequency of 6.17*10^14 Hz when stationary. In Rigel's Spectrum, it is shifted downward by 4.26*10^10Hz. What is Rigel's velocity relative to us? m/s

The correct answer will be "2.97 × 10⁸ m/s".

Explanation:

The give values are:

Observed frequency,  

Original frequency,  

Let the velocity of Rigel be = V m/s

As we know,

⇒  

On putting the values, we get

⇒  

⇒  

⇒  

⇒  

⇒  

⇒  

⇒  

So that the Rigel's velocity will be "0.99 C".

Now,

⇒  

⇒      

the answer would be c. motion and direction

i hope this : )