**Your answer seems reasonable.**

Find out if you're right!

← Where's the invisible matter?
·
Level 4
(175 points)

In a region of space are a bunch of stars in circular orbits at different radii and some unknown amount of non-visible matter. You observe the speeds of the stars and notice that the tangential velocity of each star is a constant \(v_0\), independent of radius. If the non-visible matter is distributed spherically symmetrically around the center of the galaxy, what is the ratio of the density of the non-visible matter at some distance 10R to the density at some distance R?

**Details and assumptions**

- You may assume the total mass of the stars is negligible compared to the mass of the non-visible matter.

Find out if you're right!

Sign up to access problem solutions

That seems reasonable. Find out if you're right!

Are you feeling smart or lucky? Find out if your answer is correct.

Already have an account? Log in here.

×

Problem Loading...

Note Loading...

Set Loading...