Rotational Kinematics?

Question

An auto race is hed on a track. A car completes one lap in a time of 18.9s with an average tangential speed of 42.6m/s. Find the average angular speed and the radius of the track.

Answer 1

The relationship between linear (your problem says tangential) velocity v and angular velocity w is

v = r w

You know v and w ( 2 pi radians per 18.9 seconds) so solve for r.