3B SCIENTIFIC PHYSICS 1018466 Manual De Instrucciones página 9

6. Operation
6.1 Moving the pendulum rod

Use gentle pressure to move the pendulum in
the direction of the arrow with several pushes
at the position marked until the deflection is
about 5 cm.
Note: Larger deflections can lead to non-negligi-
ble measurement errors.
Fig. 4: Moving the pendulum rod
6.2 Reversing the pendulum position

Use both hands to lift the pendulum out of the
bearing plate and turn it around.

Carefully suspend the pendulum from the
bearing plate by its other fulcrum. Then carry
on as in step 6.1.
Fig. 5: Experiment set-up with light barrier and digital
counter
6.3 Period of oscillation depending on the posi-
tion of the movable pendulum bob
Additionally required:
1 Light barrier
1 Digital counter (@230 V)
or
1 Digital counter (@115 V)

Set up the light barrier under the pendulum
rod while it is stationary and connect the bar-
rier to the digital counter (see Fig. 5).

Suspend the pendulum rod from the bearing
plate in such a way that both the fixed bob
(red) and the movable bob (blue) are below
their corresponding fulcra.

Attach the movable bob in the wedge-shaped
groove nearest to the fixed bob, i.e. the low-
est one. This position will subsequently be re-
ferred to as measuring point 1 (even when
the pendulum rod is suspended above the
other fulcrum).

Measure the period of oscillation and make a
note of it..

Keep moving the movable bob from one
groove to the next and secure it (measuring
points 2 – 13). In each case, measure the pe-
riod of oscillation and make a note of it.

Now suspend the pendulum rod from the
bearing plate in such a way that the fixed pen-
dulum bob (red) is above the relevant fulcrum
and the movable bob (blue) is below its bear-
ing.

Secure the movable pendulum bob in the
wedge-shaped groove nearest to the fixed
bob, i.e. the highest one. This position will
subsequently be referred to as measuring
point 1 (see above).

Measure the period of oscillation and make a
note of it.

Keep moving the movable bob from one
groove to the next and secure it (measuring
points 2 – 13). In each case, measure the pe-
riod of oscillation and make a note of it.

Plot a graph of the periods of oscillation de-
termined in both sets of measurements as a
function of the numbers n of the measure-
ments (see Fig. 6).
4
1000563
1001033
1001032