3B Scientific Air Cushion Plate - Manual (Page 35)

35
Physical Experiments on the Air-Cushion Table
How to proceed:
Align the air-cushion table horizontally and at-
tach the magnetic barriers. Place the piston close
to barrier no. 2. Attaching the guide piece for the
magnetic piston ensures excellent guidance of the
piston rod. Place the hover discs on the experi-
ment surface so that they are located near barrier
no. 1.
Turn up the fan so that all hover discs are sure to
lift off. Shift the piston very slowly from barrier
no. 2 towards barrier no. 1 until the piston has
crossed the center of the experiment surface.
Observe the motions of the hover discs.
Result:
At first, the hover discs perform the same mo-
tions as the molecules of a gas. The smaller the
available area becomes, the stronger the impedi-
ment of the translational movements. In addition,
there are oscillations of the hover discs around
their respective location.
The hover discs change their equilibrium posi-
tion less often with time. Finally, each disc is lo-
cated in a fixed position around which it performs
oscillating and circular motions.
Interpretation:
An increase in pressure and a drop in tempera-
ture will transform a gas from the gaseous to the
liquid aggregation state. While the molecules
perform translational movements in the gaseous
state, the prevailing motions in the liquid state
Result:
Initially, the hover discs are arranged regularly
and perform oscillating and circular motions
around their respective location. Then the ampli-
tudes of their oscillations increase. Individual
discs change their position. In the end, all discs
temporarily perform translational movements in
addition to the oscillations.
Interpretation:
A rise in temperature will make a solid body melt.
While initially all lattice elements are bound to a
fixed position around which they oscillate, there
will be a subsequent superimposition of the os-
cillations and translational movements.
2.3.3 Change of the Aggregation State of a
Gas through Compression and Cooling
Components:
Air-cushion table with fan
Overhead projector
Magnetic barrier, long
2 Pieces
Magnetic barrier, short 2 Pieces
Magnetic piston 1 Piece
Guide piece for the 1 Piece
magnetic piston
Hover disc, red
21 pieces
Model simulation
Real object Model
Vessel containing Experiment surface of
the gas the air-cushion table
Walls of the vessel Magnetic barriers
Piston in the vessel Magnetic piston
Gas molecules Hover discs