If a quasar has a recessional velocity of 2.7 10 5 km/sec and is determined to be 3600 Mpc, what is the Hubble constant based on this quasar alone? Hint: Note that the units of your result should be (km/sec)/Mpc to see what arithmetic process you need to do on a calculator.

Question

Quizplus · Accepted Answer

We can use the formula v = H0d, where v is the recessional velocity in km/s, d is the distance in Mpc, and H0 is the Hubble constant in (km/s)/Mpc. Rearranging the formula, we get H0 = v/d. Substituting the values given, we get H0 = (2.7 x 10^5 km/s) / (3600 Mpc) = 75 km/s/Mpc. Therefore, the best choice is C. The Hubble constant ($H_0$) can be calculated using the formula:

$$H_0 = \frac{v}{d}$$

where $v$ is the recessional velocity of the quasar and $d$ is its distance (in Mpc).

Substituting the given values, we get:

$$H_0 = \frac{2.7	imes10^5 	ext{ km/sec}}{3600 	ext{ Mpc}} = 75 	ext{ km/sec/Mpc}$$

Therefore, the best choice is C.

If a Quasar Has a Recessional Velocity of 2