A race car moving along a circular track has a centripetal acceleration of 15.4^2. If the car has a tangential speed of 30 what is the distance between the car and the center of the track?

In uniform circular motion (circular motion at same speed), (tangential velocity) ^2/radius = acceleration towards the center of the circle (centripetal acceleration)

Also, radius is the distance to the center of the circle (track).

So, in your case, 15.4m/s^2 = (30.0m/s) ^2 / (radius)

radius = (900. m^2/s^2) / (15.4m/s^2)

radius = 58.4m