Imagine you are standing on an escalator in a shopping mall. The steps under your feet move up or down, but always at the same pace. You are carried along evenly, without being accelerated or suddenly slowed down. Your speed stays the same as long as the escalator runs at the same speed. Such a movement is called uniform motion: In every second exactly the same distance is covered.

If you see a friend at the bottom of the escalator, you can estimate quite well when she will arrive at the top. She will not suddenly dash off or stop, but move evenly. For physicists this is practical, because they can use simple formulas to calculate how far someone has travelled after a certain time. In everyday life you notice: Uniform motion feels calm and predictable, just like standing relaxed on the escalator in the shopping mall.