# Centripetal acceleration

1. Feb 6, 2008

### caccers

1. The problem statement, all variables and given/known data

I am having difficulty with a problem: A race care goes around a level, circular track with a diameter of 1.00 km at a constant speed of 90.0 km/h. Wha tis the car<s centripetal acceleration in m/s^2?

2. Relevant equations

Ac=v^2/r

3. The attempt at a solution

I'm not quite sure if I'm supposed to find the radius of the 1.00 diameter or if I simply use the 1.00 km as my radius in the above equation...?

2. Feb 6, 2008

### rock.freak667

..$$a=\frac{v^2}{r}$$

r=radius...so yes you must find the radius(which is half of the diameter!).

3. Feb 6, 2008

### Kurdt

Staff Emeritus