What is gyroscopic precession? How can you summarize rotation?

posted Nov 25, 2018, 4:44 PM by Barbara Fortunato   [ updated Dec 2, 2018, 10:28 AM ]
F 12/7

Today, we'll start class by preparing for your test on Tuesday.  You'll first read through your statements of metacognition (aka reflections) from this unit.  Based on what you think you do well and what you need to work on, and keeping in mind all of your other social and extracurricular commitments for this weekend, you'll write a concrete action plan for yourself for studying for Tuesday's test.  

Then, you'll review the topics of angular momentum and torque in order to understand the idea of gyroscopic precession. You'll see several demonstrations and try to explain them.  You'll observe the behavior of a top or gyroscope and write down your qualitative observations during its spin. You'll use what you know to work collaboratively in small groups to derive a formula for angular velocity of precession.  The following might be useful to your derivation depending on how you approach it:  The "small angle approximation" states that for small angles measured in radians (those less than about 10°), θ ≈ sin θ ≈ tan θ. (This approximation comes from the truncation of the Taylor series of the trig functions, if you've already studied that in math class.)
Image result for small angle approximation

Finally, as output to Google Classroom or Flipgrid, you'll do one of the following:
  • Find a real-life application of gyroscopes or gyroscopic precession.  (There are examples from earth science, space science, transportation, sports, technology, and lots of other topics.)  Include a picture or diagram in your document or video.  Explain how the topic is related to gyroscopes or gyroscopic precession.  Finally, explain using your findings that you can improve the performance or how other things can take advantage of the gyroscopic effects.
  • Imagine you're a toy designer.  Spinning top sales are down.  Use your knowledge of gyroscope or gyroscopic precession and your creativity to design a brand new toy that will boost spinning top sales, and explain how the toy utilizes gyroscopes or gyroscopic precession.  Include a sketch or diagram of your new toy.  
With any time remaining, we'll work on AP practice problems. 

Homework:  Rotation Test next class - Tuesday, December 11th.  Do as many AP problems as you can while following your studying action plan that you designed.  As you study, make sure to start timing yourself - each problem should only take you 15 minutes.  Topics include:  static equilibrium, tipping, center of mass and moment of inertia integrals, rotational kinematics, torque, rotational energy, angular momentum.

Also, if you're curious about today's lesson, check out this cool application and see if you can explain it:

Antigravity Wheel? (Veritasium)