Higher June 2018 Paper 2 Q14

14 The distance-time graph shows information about part of a car journey.

Distance-time graph with distance travelled in metres from 0 to 160 against time in seconds from 0 to 8; the curve rises slowly to about 20 m at 4 seconds and then increasingly steeply

Use the graph to estimate the speed of the car at time 5 seconds. (3)