The following speed-time graph shows the speeds of a cyclist on a journey lasting two hours.
Notice that.....
after 10 minutes the cyclist is riding at 30 km/h.
the cyclist is only stationery when the speed is 0 km/h.
Example question:
At how many minutes was the cyclist travelling at 45 km/h?
Answer:
70
If we look at the mark by 45 km/h and follow it down to the x-axis, we can see that it is 70 minutes.