Three different people move on the same track, which is $400\ m$ in circumference. The track has two straight portions that are over $100\ m$ in length and the two curves are each under $100\ m$ in length.
Person 1 walks straight northward on the track for 100 meters, starting at point $S$ and finishing at point $F$ 50 seconds later.
Person 2 starts out southward starting at point $S$ and runs part way around the track, finishing at the same point $F$ as person 1, in 50 seconds.
Person 3 starts out southward starting at Point $S$ and runs all the way around the track, finishing at point $S$ in 50 seconds.
Rank these three people according to the magnitude of their average velocities during their movements on the track, greatest magnitude first.