- End of Curve W N +E S Start Circle Circumference = 2r Circle Diameter = 2r r is radius Finish A sprinter runs the curve of this 200 m in 11.83 s. Assume he ran in a lane which makes a semicircle (r = 30.7 m) for the first part of the race. At 3.28 s into the race his speed is 4.1 m/s. At 7.0 s into the race his speed is 9.5 m/s. His speed after the curve was 11.4 m/s. What was the sprinter's average angular velocity at 11.83 s? Answer in deg/s.