3B Scientific Air Cushion Plate - Manual (Page 47)

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Physical Experiments on the Air-Cushion Table
2.6 Mechanical Motions
ble to demonstrate motions at very low speed.
2.6.2 Elastic Collision
Components:
Air-cushion table with fan
Overhead projector
Magnetic barrier, long
2 Pieces
Magnetic barrier, short 2 Pieces
Hover disc, orange 4 Pieces
Model simulation:
Real Object Model
Surface on which the Experiment surface of
colliding objects move the air-cushion table
Objects participating Hover discs
in the elastic collision
How to proceed:
Carefully align the air-cushion table horizontally
using the spirit levels and attach the magnetic
barriers. Place two stacked hover discs in the
middle of the experiment surface. Place the other
doubled disc in a corner of the experiment
surface, holding it with the finger and then
releasing it so that it approaches the first. Repeat
this process several times, with stronger or lesser
deviations from a central collision. Observe the
motion of both discs before and after the collision.
Result:
In case of a central collision both discs (with equal
mass) exchange their velocity and therefore their
kinetic energy. If the collision is not central, only
part of the energy will be transferred.
2.6.1 Vertical, Horizontal and Diagonal
Projection
Components:
Air-cushion table with fan
Overhead projector
Hover disc, orange
2 Pieces
Model simulation:
Real Object Model
Space in which the Experiment surface of
projection takes place the air-cushion table
Influence of the
Force resulting from
gravitational field slight inclination of the
experiment surface
Projectile Hover disc
How to proceed:
Align the air-cushion table horizontally, place the
disc in the middle of the surface and turn up the
fan until the disc is sure to float. Then tilt the
experiment surface slightly using the adjusting
screw on side no. 4. Hold the disc at the upper
edge with the pointer and then release it without
providing an initial motion. The projected image
should clearly show the acceleration of its mo-
tion. The motion should not be too fast (by se-
lecting an appropriate degree of inclination!).
After this preliminary experiment (model experi-
ment on the free fall), it is possible to demon-
strate the various trajectories of projection. It will
be necessary to select suitable starting points and
an appropriate starting speed adapted to the “fall
time” determined in the preliminary experiment.
Type of projection Starting point
vertically upwards middle of side no. 3
horizontal top of side no. 2
diagonal bottom of side no. 2
Result:
The paths correspond to the flight paths in the
vertical, horizontal and angular projection of an
object.
Interpretation:
Since the experiment surface is tilted, uniform
motions and motions with regular acceleration
are superimposed, producing motions which cor-
respond to those occurring in projections. The
slight inclination of the experimenting surface
causes only slight acceleration, making it possi-