PASCO ME-8091 Wilberforce Pendulum User Manual

Page 11

Wilberforce Pendulum

Model No. ME-8091

5. Pull on the bob to begin moving the pendulum in a vertical

direction. The crossbar will rotate as the pendulum bobs up and
down.

6. In DataStudio, click the Start button to begin collecting data.

Observe the data in real-time as the pendulum oscillates. (If using
the pendulum without a computer and interface, use a stopwatch to
time both the vertical and rotational periods of the oscillations and
the time when the periods become equal.)

7. Move the masses on the crossbar to a new position and repeat steps

4 through 6. (Encourage students to move the masses on the
crossbar to various positions to see the affect that mass position has
on the period and angular velocity. Have students adjust the
masses until the periods of the vertical and rotational oscillations
are the same.)

Note: The periods of the vertical and rotational oscillations must be
exactly the same (quantitatively equal) for the oscillations to switch
completely between the vertical and rotational modes. If the periods
are not equal, adjust the masses on the crossbar and pull the pendulum
again. This may take a few runs of trial and error.)

Table 1: Oscillatory Periods with Varying Mass on a Pendulum Bob

*To measure the period in DataStudio, use the Smart Tool to measure

the difference between wave crests or troughs.

Run
No.

Distance of
Mass from
Pendulum
Bob (cm)

Oscillatory
Period
(seconds)

Maximum
Angular
Velocity
(rad/s)

Maximum
Force
(N/m)

vertical:
rotational:

Tip: If the masses on the
crossbar are not equidis-
tant from the center, the
crossbar will not spin
smoothly.