Introduction: Slides 1-5
What is a gyroscope? What is special about a gyroscope? The definition of a gyroscope and it’s basic properties are discussed, ie. it resists tilting.
Bicycle wheel demos:
Two demos are done to introduce two principles of gyroscopes. The students will have no previous knowledge that can explain the demos
1)
Spin bicycle wheel and hold it out
vertically.
Pass the wheel to a student and ask the student to tilt the wheel.
Student
should feel that the spinning wheel resists the tilting. Can be done
with many
students as it is a demo that must be done to be believed.
2)
This demo is done by the instructor
(myself) to
avoid injuries to students and potential law suits from disgruntled
parents of
said students. The bicycle wheel is spun up to a high speed and held
out
horizontally. While standing on the lazy susan, the instructor
painfully
presses the wheel into his chest with a large force so that the wheel
stops as
suddenly as possible. This should result in the instructor rotating on
the lazy
susan in the opposite direction that the wheel was rotating. (Video)
Angular
Review of linear momentum, ie. p=mv and F=Dp/Dt
What do velocity, mass and force correspond to in Angular momentum?
Explanations of angular velocity, moment of inertia and torque.
Explaining the Demos: Slides 27-36
Principles of torque and change in angular momentum introduced earlier are used to describe why tilting the bike wheel is difficult and why stopping the bike wheel induced rotation.
Satellites and Stabilization: Slides 37-39
Explanation
of the need for a satellite to adjust and hold
its orientation. Use the two bicycle wheel demos to explain how
changing the
speed of a wheel rotates a satellite and how the rotation of the wheels
can be
used to hold orientation. The model satellite is used as a physical
manifestation of these principles and students are encouraged to try it
for
themselves.
Video 1 - Using the motors to change
orientation.
Video 2 - Using the motors to hold
orientation.