# Turning car Centripetal Acceleration behavior?

1. Sep 2, 2011

### Jacksilver

Hi all!

A professional race-car driver is asked to make 2 different "quarter-circle" turns on a racing track.
He completes them at the highest possible constant linear speed (he is well familiar with the car and the road so it's an easy task for him).

Turn 1: Radius is R1=20m. Linear velocity measured was V1.
Turn 2: Radius is R2=45m. Linear velocity measured was V2. (V2 > V1)

Question: According to Circular Motion Model (V2=A*R)
should we expect to arrive at the same Centripetal Acceleration (A) in both cases? (Suppose air resistance and is not a factor).

I guess the question is more about the behavior of Force generated by friction and how, if at all, the linear speed affects it.

2. Sep 2, 2011

### Staff: Mentor

Sounds like it to me. By 'highest possible speed' I assume they mean going to the limit allowed by friction, just before the tires start to slip.

So what does that tell you?

3. Sep 2, 2011

### xts

Centripetal Acceleration is not the only limitation on turning at high speed. It is one of the most important - it cannot exceed the friction between tyres and the surface.
But there are other limitations, resulting from car mechanics, and wheel geometry during the turn, making the force inequally distributed to the wheels (under/over-steer), differential inequally distributing force, etc. making cars to more likely to slip at the same centripetal acceleration in the tight bend than in wider one.