Calculating the speed of an object

[Nal101]

Homework Statement

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?

Homework Equations

C = 2 $$\pi$$ r
v = m / s

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?

 

[rock.freak667]

Homework Statement

and it takes 15 seconds to go around once

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

 

[DaveC426913]

Multiply by 2 (i.e. 2 trips as indicated by problem)

Where does it say this?