# Calculating the speed of an object

## 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 Helper

## 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
Gold Member
Multiply by 2 (i.e. 2 trips as indicated by problem)
Where does it say this?