# Radial Acceleration of Sun

1. Oct 14, 2009

### crazuiee

1. The problem statement, all variables and given/known data
The Milky Way galaxy (including the sun) rotates about its center with a period of 200 million years. The sun is approx. 2 X 10^20m from the center of the galaxy. What is:
A) The radial acceleration of the sun?
B) What is the net gravitational force on the Sun due to other stars in the Milky Way Galaxy?

2. Relevant equations
v=2(pi)(r)/period
a=v^2/r

I just can't get my head around the 1 revolution per 200million years. How would I work that into a velocity? And then into an acceleration?

2. Oct 14, 2009

### mgb_phys

You have the equation - you just need to know how many seconds in 200Myr

(Hint 60*60*24*365.25 * 200,000,000)

3. Oct 14, 2009

### crazuiee

Then would I divide my seconds by 2(pi)(rad) to get my answer in rad/s?

4. Oct 14, 2009

### crazuiee

To find the Net gravitational force on the sun due to other stars in the galaxy would it just be F= [mass (of sun)] [acceleration (radial acceleration that was found)]