3B SCIENTIFIC PHYSICS U52006 Manual De Instrucciones página 6

• Suspend an additional weight from the axle.
• Make the device rotate either manually or with the
help of the string.
• The gyroscope displays precession.
• Determine the rotational frequency f of the disc and
measure the period for one precession cycle T
• The relation between f and T
following equation:
I =
where R is the distance from the fulcrum of the gyro-
scope axis to the point where the additional weight
m is attached.
• Take further measurements at decreasing rotational
frequencies.
• Plot a graph of the frequency of rotation as a func-
tion of the period of a precession cycle.
• As an alternative to the method described above, the
moment of inertia I of the disc can also be deter-
mined from the straight line gradient a.
f =
• Repeat the experiment using a different added weight.
It can be determined that the precession frequency is
approximately proportional to the added mass.
Fig. 2: Precession
5.3 Nutation
• The aim of the experiment is to demonstrate nuta-
tion and to study the interdependence between nu-
tation frequency and frequency of rotation of the
disc.
• Set up the gyroscope as shown in Fig. 3 and balance
it.
• Make the disc rotate, either manually or with the help
of the string.
• A slight lateral push to the spinning axis of the gyro-
scope will initiate nutation.
• In order to make a quantitative evaluation of the
experiment, determine the period of a suitable
number of nutation cycles.
3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com • Technical specifications subject to change
.
P
is calculated using the
P
∆
D t
ω
E
m g R
π
2
4 a
• Subsequently measure the period of rotation of the
disc.
• Make further measurements at slower disc frequen-
cies
• Plot a graph of the nutation frequency as a function
of the frequency of rotation of the disc.
• The nutation frequency is proportional to the rota-
tion frequency.
5.4 Cancellation of gyroscopic forces
• As shown in Fig. 4, slide a second disc and counter-
weight along the axis and secure with the locking
ring.
• Balance the gyroscope.
• Attach the additional weight.
• Manually rotate the discs. Make sure they rotate in
the same direction. To see the direction of rotation
more clearly, you can glue a piece of white paper
onto each disc.
• Demonstrate precession and nutation.
• Now wind each end of the string in opposite direc-
tions around a different bobbin.
• When the string is pulled, both discs begin to rotate
in opposite directions with approximately the same
rotational speed.
• Demonstrate the cancellation of gyroscopic forces.
Fig. 4: Cancellation of gyroscopic forces
6
Fig. 3: Nutation