The table shows the stopping distances for a car travelling at two different speeds.
| Speed (miles per hour) | Stopping distance (metres) |
|---|---|
| 20 | 12 |
| 60 | 73 |
The car now travels at 40 miles per hour.
Estimate the stopping distance.
18 m18\text{ m}18 m
36 m36\text{ m}36 m
48 m48\text{ m}48 m
69 m69\text{ m}69 m