What is the answer for 1. b)
We are given the following data points (time(s),distance(m)):
(0,0),(5,0),(10,20),(15,20),(20,60),(25,60),(30,50),(35,50),(40,0); each point is connected to the next by a line segment.
Speed is `"distance"/"time"` . (Note that velocity takes into account direction whereas speed does not.) So we can compute the speed on each interval of time.
0-5 no distance travelled so speed is 0.
5-10 travelled 20m in 5sec so speed is 4m/sec
10-15 no distance so speed is 0.
15-20 travelled 40m in 5 sec so speed is 8m/sec
20-25 no distance so speed is 0
25-30 travelled 10m in 5 sec so speed is 2m/sec
**Note that velocity would be -2m/sec as the distance from the start is decreasing but the speed is positive. **
30-35 no distance so speed is 0
35-40 Distane travelled is 50m in 5 sec so speed is 10m/sec