#hw lb

[gillianthecat]

Optics is one area where an in-person lab would have been really helpful.

Circuits it would have been fun, and probably useful to compare reality with the ideal version, and solidify understanding by getting our hands on the wires and capacitors etc., but the simulators were good enough. But actually working with a variety of mirrors and lenses would make things like real and virtual images make so much more sense.

Maybe we're expected to know this already? But if I learned it I forgot.

Anyway here's a video that helped. Not as good as being able to manipulate them myself, but at least it explains that "real" actually means "projected", which neither my teacher nor my textbook did.

[gillianthecat]

Physics!

Mirrors and Lenses! Reflection and refraction! Real and virtual images! Convex and concave! Ray tracing! LETS GO!

[gillianthecat]

[gillianthecat]

You’ll never guess which physics principle this image of a figure skater from my physics textbook is meant to illustrate.

(It’s in the chapter on electric potential energy and capacitors.)

[gillianthecat]

Why does science keep trying to gaslight me??? The cathode is NOT the negative electrode in an electrolytic cell, the electrons are still flowing towards it! It's, by definition, still reduction, so electrons have to move towards it and it is therefore a positive electrode. It's attached to the negative terminal of the power source, yes, but that doesn't make the cathode electrode itself negative! I felt like I was losing my mind.

I guess they call the whole section between power source terminal and electrode the "cathode"? And name it based on the battery side? Which is fine, whatever, I'm sure there are valid historical reasons for those naming conventions, but you've got to explain that that's what's happening! Because just saying "negative electrode (cathode)" contradicts everything taught before and makes students (me) feel like we don't understand any of it.

[gillianthecat]

The thing about the way this course is teaching electromagnetism is it's giving me all the separate parts but it's not really explaining how they all connect. And it's fine, I can take it on faith and simply apply the equations since the exam is open book, but it's not going to stick in my head unless I understand the relationships between concepts.

So that's this afternoon's project.

[gillianthecat]

Now I've seen three different versions of the right hand rule for magnetic force 🙄 My teacher taught us one, the textbook (which she assigned us!) used another and now this khan academy video is using a third.

Which is fine, whatever, I've picked my favorite (thumb=velocity, fingers=magnetic field, palm pushes in the direction of magnetic force. For those who had burning curiosity. It was the textbook's version.) but it would make life simpler for physics students everywhere if the world agreed on one.

Are there more than three possibilities? My instinct is yes but I'm not going to try and figure it out right now.

[gillianthecat]

Can I finish these two lab reports in the next 3 hours and fifty minutes? We're about to find out!