# Calculating the speed of an object

1. Sep 22, 2009

### Nal101

1. The problem statement, all variables and given/known data
If the radius of a merry-go-round is 11 meters, and it takes 15 seconds to go around once, what is the speed of an atom at the outer rim?

2. Relevant equations
C = 2 $$\pi$$ r
v = m / s

3. The attempt at a solution

C = 3.14 * 22
(gives distance traveled, 1 trip)
Multiply by 2 (i.e. 2 trips as indicated by problem)
divide by the time, 15s
Answer was told to be wrong, I thought it rather simple, did I make a calculation error somewhere?

2. Sep 22, 2009

### rock.freak667

so what is the time period? What is the angular velocity when you get that?

3. Sep 22, 2009

### DaveC426913

Where does it say this?