Fig. shows the speed/time graph for a journey travelled by a tractor.
(a) Use the graph to describe the motion of the tractor during each of the marked sections.
OP, PQ, QR, RS
(b) Which two points on the graph show when the tractor is stationary?
(c) State the greatest speed reached by the tractor.
(d) For how long was the tractor travelling at constant speed?
(e) State how the graph may be used to find the total distance travelled during the 200 s journey.