1. © Nuffield Foundation 2011 Nuffield Free-Standing Mathematics Activity Road test © Brett Wilson

2. © Nuffield Foundation 2011 In this activity you will use data from a speed test to draw and interpret graphs. © Brett Wilson

3. © Nuffield Foundation 2011 Drivers have always been interested in how fast cars go – and how quickly they stop! Graphs provide a useful illustration of the data.

4. © Nuffield Foundation 2011 Think about… What comments can you make? Why do you think the true and indicated speeds are different? Here are some data from a speed test. Acceleration from rest TimeTrue SpeedIndicated Speed t (seconds) v (miles per hour) u (miles per hour) 2.33034 3.54045 5.55055 6.86066 9.47078 13.18089 20.59099

5. © Nuffield Foundation 2011 The brakes were also tested by measuring the distance travelled by the car in coming to rest from different speeds. The track surface was dry and maximum braking was used. Why are only dry surfaces used for the tests? How might the results be different if wet road tests were included? Brakes True speedDistance v (miles per hour) d (metres) 30 9.5 5027.5 7052.4 8598.7

6. © Nuffield Foundation 2011 Sports car accelerating

7. © Nuffield Foundation 2011 Sports car accelerating

8. © Nuffield Foundation 2011 Sports car accelerating

9. © Nuffield Foundation 2011 Sports car braking

10. © Nuffield Foundation 2011 Reflect on your work What does each graph tell you about the car’s performance during the test drive? Road test