3B Scientific Diamagnetic Levitation Apparatus - Manual (Page 2)

5
net. The graph in figure 1 shows the potential energy
of the cube if it were located at different heights within
the apparatus, assuming the ring magnets and graph-
ite plates were removed. Masses tend to move to the
place where their potential energy is the lowest. To
move them to a higher place where their potential
energy is greater one has to do work and expend en-
ergy.
Fig.1: Potential energy of the cubic magnet at different positions in
the apparatus without graphite plates and without ring mag-
nets
The next graph in fig. 2 considers the potential energy
of the cube as the result only of the nearness to the
ring magnets, assuming that gravity is not a significant
force. Its potential energy would be the lowest at a
position closest to the ring magnets. We would have to
expend energy to remove it from the magnets and it
would gain this energy as potential energy.
Fig.2:Potential energy of the cubic magnet at different positions in
the apparatus without graphite plates and no gravity
The third graph in fig. 3 shows the total potential en-
ergy of the cubic magnet in various positions within
the apparatus, when both the gravity and the attrac-
tion of the ring magnets are considered. Of special in-
terest is the area between the vertical lines, which rep-
resent the positions of the plastic plates. Fig. 4 shows
this area magnified.
Fig. 3:Total potential energy of the cubic magnet at different posi-
tions in the apparatus with plastic plates
Fig.4: Magnification of fig.3
The graph shows that the cube has the greatest poten-
tial energy at a point approximately half way between
the plastic plates. At this point the cube magnet is in
equilibrium, but it is unstable equilibrium.
If the plastic plates are now replaced by the graphite
plates, we would have to expend energy to push the
cube magnet closer to the graphite plates. Its poten-
tial energy would be greater near the graphite plates.
The graph in fig. 5 shows this fact.
Fig.5: Potential energy of the cubic magnet between the graphite plates
P
o
tential energ
y
Bottom Position in bell housing Top
P
otential energ
y
Bottom Position in bell housing Top
P
otential energ
y
Bottom Position in bell housing Top
P
o
tential energ
y
Bottom Position in bell housing Top
P
otenzielle Energie
Grafitplatte Grafitplatte
Position des NdFeB-Magneten