Imagine you are sitting in an ICE that is travelling on a high-speed line. At the station the train is still standing, then it begins to accelerate: You are pushed slightly into the seat because the train is getting faster and faster. After some time it has reached its travelling speed, for example 250 or even 300 km/h. From then on it suddenly feels calm again. The train is travelling extremely fast, but its speed now remains roughly constant, like the cruise-control car, only much faster.

For the ICE to go this fast, it first has to accelerate uniformly for a while. That means its speed increases by approximately the same amount every second. When it has reached the desired speed, it then stays as constant as possible, as long as there is no curve, no station or any other obstacle. On the display in the carriage you then see a large number that hardly changes. In this way, on a single train journey you first experience accelerated motion and then an almost uniform motion, all in a real technology adventure outside your window.