A runner hopes to complete the 10,000 m run in exactly 30 minutes. After exactly 27 minutes, there are still 1100 meters to go. The runner must accelerate at .20 m/s^2 for how many seconds in order to achieve the desired time? Assume the runner ran with constant velocity for the first 27 minutes. Here's what I did: 8900 m/27 minutes 8900 m = .5(V0 + Vf)1620 s Vo + Vf = 10.9 m/s Vf= 5.5 m/s 1100 m = 5.5t + .5(.2 m/s^2)t^2 t= 80.9 seconds Is this right?