3B Scientific Air Cushion Plate - Handbuch (Seite 84)

33
Physical Experiments on the Air-Cushion Table
the magnetic barriers. Spread the hover discs
evenly across the experiment surface.
Adjust the airflow strong enough to ensure that
the hover discs lift off even when the impulse
valve is opened. Briefly open the impulse valve
several times so that the hover discs have a high
mean kinetic energy. Observe the motions of the
hover discs.
Result:
At first, the hover discs perform oscillating and
circular motions superimposed on their
translational movements. Their mean kinetic
energy gradually drops. The amplitudes of the
oscillations decrease, translational movements
occur less often. After a while there still are
occasional exchanges of position. Finally, each
hover disc only moves around its own equilibrium
position.
Interpretation:
Reducing the temperature of a liquid leads to its
solidification. The drop in temperature causes a
drop in the mean kinetic energy of the molecules
of the liquid. In the process of solidification, each
molecule occupies a specific location, around
which it performs irregular oscillating motions.
Note:
The mean velocity of the hover discs will drop
faster when the fan is turned to a lower setting.