Students use the same ruler-drop method to test the effect of a distraction. Smaller falling distances correspond to shorter reaction times. The table shows the results for one student.
| Condition | Distance in trial 1 in cm\mathrm{cm}cm | Distance in trial 2 in cm\mathrm{cm}cm | Distance in trial 3 in cm\mathrm{cm}cm |
|---|---|---|---|
| No distraction | 18 | 20 | 22 |
| With distraction | 24 | 26 | 28 |
Which conclusion is supported by these results?
Distraction increased every driver’s reaction time, and the increase was exactly 30%.
Distraction decreased this student’s reaction time, but the decrease was not necessarily 30%.
Distraction decreased every driver’s reaction time, and the decrease was exactly 30%.
Distraction increased this student’s reaction time, but the increase was not necessarily 30%.
126 exam-style questions on Edexcel GCSE Physics 2.5 Stopping and braking distances, covering 2.5.1 Stopping distance and reaction time, 2.5.2 Factors affecting stopping distance, 2.5.3 Dangers of large decelerations, and 2.5.4 Braking distance and initial speed. Each one has a worked solution and a mark scheme showing where the marks go.