A learner driver uses a computer reaction timer. The screen changes after a random delay and the learner clicks as soon as the screen changes.
The learner repeats the test five times.
| Test | Reaction time in s\text{s}s |
|---|---|
| 1 | 0.32 |
| 2 | 0.31 |
| 3 | 0.80 |
| 4 | 0.30 |
| 5 | 0.31 |
Give the anomalous reaction time.
The anomalous result is not used.
Calculate the mean reaction time for the other four results.
Give one reason why calculating a mean from repeated readings gives a more reliable result than using one reading.
The learner later drives a campervan at a constant speed of 15 m/s. The instructor uses the mean from (b) as an estimate of the learner's reaction time while driving.
Use the equation
d=vtd=vtd=vt
to calculate an estimate for the thinking distance.