Recent content by Herman Trivilino

I start with a chart showing the values of ##v## and ##\gamma## for the motions of different objects. Starting with maybe a race car, then a bullet, and so on up to the speed of Earth orbiting the sun, showing that what we think of as everyday speeds have a value of ##\gamma \approx 1##. Then I...

Well, we create models. That's physics. Describe and predict the way Nature behaves using models. No, because we have additional observations and evidence other than just the shadow. Yup. Like that! The model of light as a wave gained traction with the work of Maxwell and others. Later...

It's not moving only at the instant it makes contact.

Those are not the most basic axioms of thermodynamics. By "simply taught" I assume you mean only a spoken or written explanation is provided. But they can also be demonstrated or they can be incorporated into a student activity. It depends on the instructor. Cold water sinking and hot water...

I would guess that the determining factor would be the traction of the hooves, which of course depends on the soil conditions. I doubt the rider's position would make a significant difference but I would experiment with different positions. Of course the horse's motivation is a dominant factor...

Nope. Just nope. Pushing the water through faster, even if it produced water, the water would not be filtered.

I can't speak for the OP and I don't know if you're referring to this equation in particular or in general. But this is what I would mean for the equation ##v=v_o +at##. I would start with students performing guided activities in front of an ultrasonic motion detector or the like, connected to...

##\vec{L} = \vec{r} \times \vec{p}## does imply the relationship between the directions of ##\vec{L}## and ##\vec{\omega}##. So the latter is a consequence the former.

But even in those cases the direction of ##\vec{\omega}## relative to the direction of ##\vec{L}## is a consequence of the definition ##\vec{L}=\vec{r}\times\vec{p}##. Is it not?

Note these are consequences of the definition of angular momentum: ##\vec{L}=\vec{r} \times \vec{p}##.

That's a common misuse of the terminology. We refer to a rest frame as a frame of reference in which something is at rest. So the correct phrasing would be to simply state that you are at rest in your "impossible" frame of reference. Or the "impossible" frame is your rest frame. It's good that...

By spindle "changing" you mean ##\vec{\omega}## of the rotating object changing direction? Then, yes.

That follows from the definition of angular momentum. He states "torque due to gravity". So you don't see that a torque by definition requires a force? Or you don't see where the force of gravity comes from?

What do you mean by enter a reference frame? What are you trying to learn?

The thing is, without data to support that conclusion we have, well, no data to support it!