# The motorist

**Classical Mechanics**Level 2

A motorist travelling at \(13 \text{ ms}^{-1}\) approaches a traffic light which turns red when he is \(25\text m\) away from the stop line. His reaction time (i.e. the interval between seeing the red line and applying the brakes) is \(0.7\text s\) and the condition of the road and his tyres are such that the car cannot slow down at a rate of more than \(4.5 \text{ ms}^{-2}\). If he brakes fully, how far from the stop line will he stop, and on which side of it?