Comments by "EebstertheGreat" (@EebstertheGreat) on "Spinning Tube Trick Explained" video.

  1. jsdsparky Centrifugal force always arises in a rotating reference frame. It is very useful when doing physics in a rotating reference frame. It was invented by physicists. Don't hate on pseudoforces.
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  2. jsdsparky It isn't niche. People work in rotating reference frames all the time. When you do, you need to include fictitious forces like the centrifugal force and the Coriolis force. Furthermore, saying that water stays in the bucket due to the centrifugal force is correct, in the reference frame of the bucket. It's the same reason you feel an inertial force pushing you to the back of your seat when you accelerate in a car. It's a good analogy, but I agree it's better if you also explain that the reason for the effect is inertia, not any fundamental interaction (that's why they're also called "inertial forces"). But keep in mind that in elementary school, nobody knows the laws of motion, so you're not going to be able to give a complex answer based on kinetics.
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  3. jsdsparky That's why I said in a rotating reference frame. It's also why I explicitly pointed out that these kids don't know the laws of motion and that it's called an inertial force. It's like you're repeating my exact post. And yes, of course I've taken physics. In any advanced mechanics class, e.g. Physics C, you will learn how to transform laws in an inertial reference frame to a non-inertial one, including constant acceleration (including rotation). In a reference frame rotating at a constant angular velocity, you get the Coriolis force and the centrifugal force. In a rotating reference frame with nonconstant angular velocity, you also get the Euler force. They fall directly out of the laws of motion.
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