Model No. ME-6834
Discover Rotation Platform
5
!
Suggested Experiments
Moment of Inertia Experiments
Students can both qualitatively and
quantitatively investigate the moment of
inertia with the Discover Rotation Platform.
1.
Ask a student to sit on the stool of the
Discover Rotation Platform with 5 kg
masses in each arm (see Figure 6).
2.
Have the student sitting on the stool (the
rider) extend his/her arms outward.
3.
Have another student (or lab partner) rotate
the rider.
4.
After gaining speed, ask the rider to pull the
masses into his/her chest. Qualitatively, the
rider and observers will notice the increase
as the masses are pulled toward the center
axis of rotation.
5.
Use a photogate to provide quantitative measurements of position,
velocity, and acceleration.
Using the expression
, students can relate the angular acceleration
that results when the masses are moved inward to a decrease in the
moment of inertia of the system.
Torque Experiments
By applying different torques to the platform and using the photogate
to measure the angular acceleration, students can produce a graph to
help them discover the moment of inertia for the system.
1.
Attach the Photogate Head to the bottom platform.
Figure 6
τ
I
α
=
Figure 7
Warning:
Ask students
to tightly grip the
weights with their
hands and fingers. To
avoid injuries, always
enforce appropriate
safety precautions in
the classroom.
Note:
For optimal
rotation, keep the
stool on a hard floor.
The stool may not
rotate on carpeting.
