3B Scientific Air Cushion Plate - Handbuch (Seite 97)

47
Physical Experiments on the Air-Cushion Table
2.5 Nuclear Physics
Result:
The hover disc changes its direction of motion
near the stacked magnets. This change in the di-
rection of motion is stronger the lower the veloc-
ity of the hover disc is and the closer the path
runs along the stacked discs.
Interpretation:
Charged particles are scattered near the atomic
nucleus. The scattering angle depends on the
velocity and the initial direction of the particles.
2.5.2 Scattering of Alpha Particles When
Passing Through a Metal Foil
Components:
Air-cushion table with fan
Overhead projector
Magnetic barrier, long
2 Pieces
Magnetic barrier, short 2 Pieces
Magnetic barrier consisting 1 Piece
of 4 magnets
Hover disc, red
1 Piece
Model simulation:
Real Object Model
Space in which the Experiment surface of
alpha particles move the air-cushion table
Metal foil
Magnetic barrier made
of 4 magnets
Atomic nuclei Ceramic magnets of the
barrier
Alpha particles
Hover discs
How to proceed:
Carefully align the air-cushion table to a hori-
zontal setting using the spirit levels. Attach the
magnetic barriers, turning barrier no. 2 by 180°
so that it holds the approaching hover disc. Place
the ends of the magnetic barrier consisting of 4
magnets into the recesses provided in barriers no.
3 and 4 which are located near barrier no. 2.
Turn the fan to a setting in which the hover disc
floats freely. Move it closely to barrier no. 1. Hold
it with the finger at first, then suddenly release it
so that it hits the barrier of 4 magnets at high
velocity.
Repeat the experiment with slight variations of
the starting position. Observe the motion of the
hover disc through the magnetic barrier.
Result:
In most cases, the hover disc will pass through
2.5.1 Scattering of Positively Charged
Particles Near an Atomic Nucleus
Components:
Air-cushion table with fan
Overhead projector
Holding device
Plexiglas plate
Hover disc, orange
5 Pieces
Model simulation:
Real Object Model
Space in which the Experiment surface of
positively charged the air-cushion table
particles move
Atomic nucleus
Stacked hover discs
Positively Hover disc
charged particle
How to proceed:
Carefully align the air-cushion table to a hori-
zontal setting using the spirit levels. Attach the
holding device to the air-cushion device and in-
sert the Plexiglas plate.
Place the 4 stacked discs in the middle of the
Plexiglas plate with their magnets facing down-
wards. This is to ensure repulsion of the hover
disc on the experiment surface. Set this disc into
motion at the lowest possible velocity from the
edge of the experiment surface towards the
stacked magnets.
Repeat this experiment at various speeds. Then
vary the direction of motion, making the hover
disc float along the stacked magnets at gradually
increasing distances from experiment to experi-
ment.