The correct answer is circular. Copernicus and other astronomers before him thought that celestial bodies followed a circular orbital path. Copernicus was a Polish astronomer that concluded that the sun is at rest near the center of the universe and the earth is revolving around it annually. This theory is called heliocentric.
V o = 6 m/s, t = 2 s v = 10 m/s v = v o + a t a t = v - v o a = ( v - v o ) / t a = ( 10 m/s - 6 m/s ) / 2 s = 4 m/s / 2 s = 2 m/s² Answer: The runner`s acceleration is 2 m/s².
