Arunner is running to the left with a speed of 8.0\,\dfrac{\text m}{\text s}8.0 s m 8, point, 0, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction when she speeds up with constant acceleration for 2.0\,\text s2.0s2, point, 0, start text, s, end text to reach the finish line. the runner's final speed is 9.9\,\dfrac{\text m}{\text s}9.9 s m 9, point, 9, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction to the left. what was the runner's acceleration as she sped up to the finish line?