Question

It is possible to derive the age of the universe given the value of the Hubble constant and the distance to a galaxy, again with the assumption that the value of the Hubble constant has not changed since the Big Bang. Consider a galaxy at a distance of 400 million light-years receding from us at a velocity, v. If the Hubble constant is 20 km/s per million light-years, what is its velocity

Answer 1

v = 8000 km/s = 8 x 10⁶ m/s

Step-by-step explanation:

The velocity of the galaxy is given by the following formula:

`v = cd`

where,

v = velocity of the galaxy = ?

c = Hubble's Constant = 20 km/s.million light years

d = 400 million light years

Therefore, using these values in the equation we, get:

`v = (20\ km/s.million\ light\ years)(400\ million\ light\ years)`

v = 8000 km/s = 8 x 10⁶ m/s