3B Scientific Air Cushion Plate - Handbuch (Seite 66)

15
Physical Experiments on the Air-Cushion Table
Note:
This experiment can be developed from the one
described above in 2.1.1. by placing three additional
orange hover discs onto the experiment surface one
after the other while keeping the fan turned on. The
collisions between the discs and the transfer of
kinetic energy caused by them can be especially well
observed when using a low number of discs.
2.1.3 Dependence of the Number of Impacts
with the Vessel Wall on the Velocity of
the Molecules
Components:
Air-cushion table with fan
Overhead projector
Magnetic barrier, long
2 Pieces
Magnetic barrier, short 2 Pieces
Hover discs 2 Pieces
Stop watch or master clock l Piece
Model simulation
Real Object Model
Vessel containing Experiment surface of
the gas the air-cushion table
Walls of the vessel Magnetic barriers
Gas molecules Hover discs
How to proceed:
After aligning the air-cushion table horizontally,
attach the magnetic barriers.
Turn the fan to a setting in which two hover discs
placed above each other are sure to lift off. Give
this doubled hover disc an impact so that it hits
one of the barriers in the middle at an angle of
45°. Count the impacts with the wall occurring
within a given period of time (10 seconds).
Then repeat the experiment with only one of the
hover discs at a higher velocity.
Result:
The higher the velocity of the hover disc is, the
more often it will hit the magnetic barrier within
a specific period of time.
Interpretation:
The higher the velocity of the molecules is, the
more impacts of the gas molecules will occur with
the vessel wall. Since these impacts cause the
pressure, higher molecule velocities cause high-
er pressure.
Note:
The hover disc can also be set into motion so that
it hits the barriers at a perpendicular angle.
2.1.4 Dependence of the Number of Impacts
with the Vessel Wall on the Volume
Components:
Air-cushion table with fan
Overhead projector
Magnetic barrier, long
2 Pieces
Magnetic barrier, short 2 Pieces
Hover disc, red l Piece
Hover disc, grün l Piece
Stop watch or master clock
Model simulation
Real Object Model
Vessel containing Experiment surface of
the gas the air-cushion table
surrounded by magnetic
barriers
Walls of the vessel Magnetic barriers
Gas molecules Hover discs
How to proceed:
Align the air-cushion table horizontally and attach
the magnetic barriers.
Turn the fan to a setting in which the hover discs
are sure to lift off. Then place both hover discs
into one corner of the experiment surface, first
holding them with two fingers and then quickly
releasing them. Count the number of impacts one
of the discs performs with the vessel walls within
a specific period of time (5 seconds).