Physics Dimensions Level: University

A racecar traveling at constant speed makes one lap around a circular track of radius r in a time t [ NOTE: the circumference of a circle is given by C = 2 pai r]. Determine the magnitude of the average velocity of the car one complete lap.
a. r/t
b. 2r/t
c. pai / t
d. 2 pai r / t
e. zero m / s