[单选题]
A cart starts from rest and;03v0drt zg9/ w pnrop accelelj6pcjz 9x ua*a(+6f px:svl5vsxq8,rates at $4.0 \; m/s^2$ for 5.0 s, then maintain that velocity for 10 s, and then decelerates at the rate of $2.0 \; m/s^2$ for 4.0 s. What is the final speed of the car?
