>>foreig+59
Drag a marker with a constant radial velocity (from your perspective) across a spinning disk. It'll trace out a curved line, so from the perspective of an observer on the disk, an acceleration must have been present.
The full 3d Coriolis force is more complicated than that (eg accounting for the Eötvös effect): The spinning disk example only gets you to the -2vω term (where v denotes radial velocity and ω angular velocity).