1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution A) Mean velocity is defined as <v> = total distance traveled/ total time taken = πR/Γ = 0.5 m/s B) How is part a) different from part b)? I think what Irodov means by mean velocity is mean speed in part a. It is mean speed which is defined as <v> = total distance traveled/ total time taken . In part b, <v> is defined as <v> = total displacement traveled/ total time taken in the direction of total displacement |<v>| = R/Γ = 0.32 m/s Have I understood the difference between mean velocity and modulus of mean velocity vector properly? How to calculate part c?