Dr Johan Lindén who is a lecturer at the Faculty of Science, Åbo Akademi University, Finland, has investigated the (famous) upside down glass of water experiment.
But with a crucial variation – the card has a hole cut in it. Nevertheless, the water still stays in the glass – providing that the hole is small enough. The question arises – what size hole is too big?
A set of quasistatic numerical simulations based on hydrostatic pressure and surface tension of water showed the maximum diameter of the hole to be 15.25mm. Subsequent practical experiments put the figure at 15.1mm.
Here is a video, done by a different experimenter, who has a classic teachable-moment smiley-teacher demeanor, about the classic upside-down experiment:
See: Upside down glass of water experiment revisited Physics Education, Volume 55, Number 5
Note: Dr Lindén has also investigated the Mechanical resonance in the rear wheels of a shopping trolley
Research research by Martin Gardiner