A car is tested on three different road surfaces. The car, the driver and the speed are the same in each test.
The Table shows the results.
Table
| Road surface | Thinking distance in m\text{m}m | Braking distance in m\text{m}m |
|---|---|---|
| dry | 15 | 38 |
| wet | 15 | 75 |
| icy | 15 | 190 |
Explain why the thinking distance is the same for all three road surfaces.
Explain why the braking distance is greater on the wet road than on the dry road.
Calculate the percentage increase in the stopping distance of the car when the road changes from dry to wet.
The car is then loaded with heavy luggage and tested on the dry road at the same speed.
Explain how the braking distance changes.