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x2017

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## Homework Statement

A sprinter runs the curve of this 200 m in 11.61 s. Assume he ran in a lane which makes a semicircle (r = 32.4 m) for the first part of the race. At 3.59 s into the race his speed is 5.9 m/s. At 7.9 s into the race his speed is 8.4 m/s. His speed after the curve was 12.4 m/s.

What was the sprinter's average angular acceleration after 11.61 s? Answer in deg/s2. I.e., what was his average acceleration while running the curve?

## Homework Equations

α=Δω/Δt

ω=Δθ/Δt

## The Attempt at a Solution

ω=Δθ/Δt

ω=180/11.61s

ω=15.50degrees/s

α=Δω/Δt

α=15.50degrees/11.61s

α=1.34degrees/s2My answer is wrong and no matter what I do I can't get it right. The way my professor does assignments is we either get 100% or 0% and so I'm very frustrated and would really really appreciate some help. Physics is very difficult for me.