Physics I

Spring 2020

Tue April 21


First : let's go over any of the homework that you would like. We covered quite a lot in this 2D rotation stuff:

Discuss, and practice as needed.

Depending on how this feels, this week I'd like you to look into some of how the 3D stuff works.


Second : what happens in the full 3D case?

The full answer is beyond the scope of this class. I am not sure yet how many problems we want to look at for this stuff. At least the basic precession equation, which is in the textbook.

The key point is that the torque, angular momentum, and spin vector all have both direction and length. And they can all point in different directions.

The definitions depend on what you decide is the coordinate system origin, similar to how the notion of potential energy depends on where you put zero.

For this class, the goal is to at least be exposed to a few specific iconic situations.

I am used to the explanations in chapter 7 of Kleppner - Kolenkow, particularly the off-axis baton, and examining the motion of two opposite points on a spinning wheel, and how their motion is changed by an applied force that tries to twist the wheel.

Discussion : /cours /spring2020 /mechanics /notes /apr21
last modified Sun October 17 2021 11:56 am

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