A height-time diagram is shown here as an example. The aim is to correctly describe the time behavior of the height $$h(t)$$ of a body thrown vertically upwards. Three conceivable time curves are drawn in, which have a different action $$S[h]$$ (in joules seconds). The path with the smallest action (2 joules seconds) corresponds to a parabola and is "chosen" by the thrown body.