You are members of the police who go to the scene of a traffic accident.
At the scene there are two cars, one of which has obviously run into the back of the other. There are also brake marks on the road. After examining the scene of the accident you conclude that one of the cars, a 1L Volkswagen Polo hatchback was parked with its handbrake on and only the driver in it before the accident, while the other car, an A class Mercedes A140L had a single male occupant (35 years old) and crashed into the back of the Polo. Both cars were empty except for their drivers. The point on the road where the impact took place is indicated and you notice brake marks leading up to the impact and brake marks after the impact. After the impact the cars were stuck together. The accident took place in a 40 mph zone and the road was dry. It is your task to determine if the person driving the Mercedes was speeding.
There is a technical expert at the scene of the accident who will make any measurements you ask for.
The police don't do these calculations themselves because they weren't selected on their mathematical abilities. There are computer programs to do this for them. They just type in all the parameters and the answer just pops up on the screen. Jus like that!