An athlete is training on a 100 m long linear track. His motion is described by the graph of his position vs. time, below.(a) For each segment of the graph, find the magnitude and direction of the athlete's velocity.

magnitudevA	m/s
directionvA	---Select--- positive x negative x The magnitude is zero.
magnitudevB	m/s
directionvB	---Select--- positive x negative x The magnitude is zero.
magnitudevC	m/s
directionvC	---Select--- positive x negative x The magnitude is zero.
magnitudevD	m/s
directionvD	---Select--- positive x negative x The magnitude is zero.

(b) What are the magnitude and direction of the athlete's average velocity over the entire 60 s interval?

magnitude	m/s
direction	---Select--- positive x negative x The magnitude is zero.