In order to keep this section simple, we'll only try to do the calculations for objects on a turn of constant radius.

In order for a mass (**M**) to move around a circle of constant radius (**r**)
it must be subject to a centripetal force of magnitude

acting perpendicular to the direction of motion (Tipler, p. 65).

This force is generated by the tyres, however, the total force that a tyre can generate is limited. The art of race driving is to balance the accelerating (braking) and cornering forces so that the total force stays within the `traction limit'.

**Figure 8:**
The traction circle showing a car accelerating out of a right hand
bend, close to the limit of traction.

Thursday October 8 16:09:30 BST 1998