Graphs in practical situations — practice question

A car begins from rest and accelerates uniformly at $0.7\,\text{m s}^{-2}$ for 20 seconds, so that it then attains a steady speed of $14\,\text{m s}^{-1}$. After that, it continues at $14\,\text{m s}^{-1}$ over a distance of $210\,\text{m}$. Next, the car slows down at a constant rate of $1.4\,\text{m s}^{-2}$ until it stops. A speed-time grid is shown.