Next, we used a computer simulation to help students
understand what is occurring with molecules in
a stream of air. The simulation shows how molecules
in the air interact when a force is exerted on them
(available at http://home.earthlink.net/∼mmc1919/
venturi discuss nomath.html). From the demonstration,
students were able to explain that in a stream
of air molecules are all moving in the same direction
and that the collisions among molecules are less frequent
compared to air molecules in stationary air. In
other words, as a flowing gas gains speeds, the internal
pressure in the gas decreases in relation to the surrounding
air. (For a mathematical explanation of Bernoulli’s
principle, see Hewitt 2004.)