A child is practicing for a BMX race. His speed remains constant as he goes counterclockwise around a level track with two straight sections and two nearly semicircular sections as shown in the aerial view of Figure OQ6.3. 

(a) Rank the magnitudes of his acceleration at the points A, B, C, D, and E from largest to smallest. If his acceleration is the same size at two points, display that fact in your ranking. If his acceleration is zero, display that fact. 

(b) What are the directions of his velocity at points A, B, and C? For each point, choose one: north, south, east, west, or nonexistent. 

(c) What are the directions of his acceleration at points A, B, and C?

 

B N A. Co w E S D E Figure OQ6.3