The presenter talks to a policeman about how the speed of a car is calculated. They look at how fixed marks and known distances are used to calculate speed. This is done by measuring the time it takes a vehicle to travel the known distance, and then using the formula, "speed = distance/time", to calculate the speed. This same method is used on the two pictures from a speed camera. which show how many fixed marks a vehicle passes in half a second.
Using speed, distance and time equations, students can calculate the average speed of various activities happening around the school. Depending on the activities involved, this could involve simple observation and use of stopwatches, or could be carried out with light gates and/ or video equipment. Discuss differences between instantaneous and average speed and introduce the idea of acceleration.