Question

2. Galaxy X in the Virgo Cluster has a cosmological redshift in its spectrum of z = 0.003 indicating it is moving away from us at 900 km/s. Galaxy Y has z = 0.015 a) Using z = v/c and our math shortcut, how fast is Galaxy Y moving away from us? (You can review the method in Box 23-2.)

Answer 1

Speed of Galaxy Y is 4500 km/s

Step-by-step explanation:

As we know that the Galaxy X has redshift given as

`z = (v)/(c)`

`0.003 = (900 km/s)/(c)`

`c = 3* 10^5 km/s`

now in similar way for galaxy Y we have

`z = 0.015`

so we will have

`0.015 = (v)/(3 * 10^5)`

`v = 4500 km/s`