3B SCIENTIFIC PHYSICS 1018466 Manual De Instrucciones página 8

3. Description
The reversible pendulum is a physical pendulum
with two bearing fulcra plus one fixed and one
movable pendulum bob. It oscillates in its stand
either with a period of oscillation T
bearing fulcrum or period T
crum. By shifting the movable pendulum bob it is
possible to adjust both these periods until they
are equal. The pendulum then has a reduced
length equal to the distance d between the bear-
ing axes and the following equation applies:
d
   
g: acceleration due to gravity
T T 2
,
1 2
g
When it is moved, the movable weight latches
into place every 2.5 cm. For finer movements the
bob can be turned by 180° about the vertical and
mounted that way round.
4. Technical data
Period of calibrated
pendulum (calculated
assuming g = 9.81 m/s
Overall dimensions:
Overall weight:
Length of pendulum rod:
Separation between
bearing fulcra:
Fixed pendulum bob:
Movable pendulum bob:
Pendulum deflection
5. Set-up
5.1 Choice of set-up location
If the floor on which the equipment is set is
springy, then the oscillation energy is transferred
to the whole stand and measurement errors can
then arise.

Only set up and use the reversible pendulum
on solid, level ground.
On smooth, slippery or sensitive surfaces:

Put a mat under the base plate and the strut
of the stand.
5.2 Assembly of stand

Undo the screw (see Fig. 1), fold out the
stand rod.

Secure it in its operating position with a mod-
erate degree of torque.
about the first
1
about the second ful-
2
2
): 1794 ms
80x125x30cm
6.3 kg approx.
120 cm
80 cm
1.4 kg approx.
1.0 kg approx.
max. 10 cm
Fig. 1: Attachment of stand rod to stand board
5.3 Vertical positioning of the pendulum rod

Grip the pendulum with both hands and care-
fully suspend it from the bearing plate (see
Fig. 2).

The vertical positioning of the pendulum rod
should be adjusted using the positioning
screws in such a way that the bubble of the
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spirit level is centered (see Fig. 3).
Fig. 2: Bearing plate with pendulum rod suspended
Fig. 3: Setting position with the help of the spirit level
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