Rain of Balls
A demonstration to show that a series of impulses is quite similar to application of a constant force.
This is broadly demonstrative of air pressure, as well.
A tube filled with bearing balls is fed via a screw into a dropper so that the balls fall at a constant rate. They fall onto a mechanical balance from a height of 1 meter. A laser is reflected off of the balance and calibrated so that the scale in the background represents grams.
That pony-tailed nerd is me.