• 0 Posts
  • 15 Comments
Joined 5 months ago
cake
Cake day: June 4th, 2025

help-circle
  • Some others have said some good things, but I’ll add a few more comments:

    Objects will continue moving in the same direction at constant velocity unless acted upon by an outside force. In the circular motion case, as you correctly state, the velocity vector is always perpendicular to the acceleration vector, which does point inwards towards the center of the circle. The object IS accelerating inwards – the water in the bucket in your example is accelerating inwards. It’s just that it is also already moving tangential to the circle and the result of the inwards acceleration is the object turning to follow the circular trajectory. It’s distance from the center remains constant instead of increasing.

    This is all the ideas of centripetal acceleration from a stationary frame of reference outside of the water-bucket system. There is no extra centripetal force. In your water-bucket example, there is a force the bucket applies against the water to give the water its centripetal acceleration. Some people call this a centripetal force, but I don’t like that phrasing, because it sounds like its an extra force. A water-filled bucket sitting on the ground also exerts a force upwards on the bucket. We typically call this a normal force, so in the spinning example, the normal force of the bucket against the water is causing the water to move in a circle. Likewise, the string tied to the bucket - the string is exerting an inwards tension force on the bucket that causes the bucket to travel in a circle, and thus have centripetal acceleration. If you cut the string, the bucket stops turning and instead goes in the straight path in the direction of its velocity vector.

    Now, think of the fictitious centrifugal force as from the frame of reference of someone moving in the circle. I like to use the example of you sitting in a school bus with those slick plastic-leather seats as the bus goes around a turn. You “feel” like you’re being pushed outwards. In actuality, there is insufficient frictional force to keep you turning in the same circle as the bus, so you are traveling in the straight line that your velocity vector is pointing. Thus you “feel” like you are being pushed outwards. The term centrifugal force arises because that “feel” can be modeled mathematically from the perspective of the rotating object, and we call it a centrifugal force. This term is mathematically equivalent to the centripetal acceleration term from the previous stationary frame of reference.



  • My only suggestion would be to go down slower. Otherwise I think you’ve got good form. Don’t worry too much about the weight. Just slowly increase the reps or weight when possible.

    You might be able to fiddle with feet position to get as low without the plate. But there’s nothing really wrong with using the plate.

    Are your legs/glutes sore after? That’s what really matters.


  • Like how small? I tile on my 14" laptop screen and still infinitely prefer it over floating. Workspaces exist so you don’t clutter up one screen too much. Maybe people aren’t familiar with or used to taking advantage of multiple workspaces? I started using them more when i3 introduced me to a simple super+number hotkey system to switch quickly.




  • Yeah, it was a revelation when I discovered tiling. I was always doing work with two windows open, and i’d spend so much time fiddling and resizing the windows. Then i’d open a third window and wouldn’t know what to do with it.

    I used i3 for many years and switched to sway when migrating to wayland. It does what I need and see no reason to try hyprland or other tilers.



  • Yeah agree. I do deficit deadlifts and pullups, 5 sets each, on the same day, and they drain me so much that i usually only do 1 or 2 more exercises on those days.

    He also didn’t say how many days per week he was gonna lift. I also don’t like PPL for my schedule, which is one lift day every third day, as it doesn’t hit legs enough.

    I’ll also edit and add that a bunch of his listed exercises are isolated machines and so may be less fatiguing and thus might be able to get away with less rest and fit it all in a reasonable time.



  • There’s tons of youtube videos / tutorials on how to create a live usb of a distro, such as linux mint. This will allow you to boot into linux and play around without installing anything and get a feel for linux. It’s nowhere as tech wizardry as you think.

    And if all your games are on steam and don’t have anti cheat things, they’ll probably just all work with proton (linux compatibility tool in steam).


  • Yeah, that fake competence is a big thing. Physics Education Research has become a big field and while i don’t follow it too closely, that seems to be a reoccuring theme - students think they are learning the material with such reliance on AI.

    I intend to read a bit more of this over the summer and try to dedicate a bit of the first day or two next semester addressing how this usage of chatgpt hurts their education. I teach a lot of engineering students, which already has around a 80% attrition rate, i.e. 200 freshman, but only 40 of these graduate with an engineering degree. Probably won’t change behavior at all, but I gotta try something.



  • This is mostly the purpose of my homework. I assign daily homework. I don’t expect students to get the correct answers but instead attempt them and then come to class with questions. My lectures are typically short so that i can dedicate class time to solving problems and homework assignments.

    I always open my class with “does anyone have any questions on the homework?”. Prior chatgpt, students would ask me to go through all the homework, since much of my homework is difficult. Last semester though, with so many students using chatgpt, they rarely asked me about the homework… I would often follow up with “Really? No questions at all?”


  • Chatgpt output isn’t crap anymore. I teach introductory physics at a university and require fully written out homework, showing math steps, to problems that I’ve written. I wrote my own homework many years ago when chegg blew up and all major textbook problems were on chegg.

    Just two years ago, chatgpt wasn’t so great at intro physics and math. It’s pretty good now, and shows all the necessary steps to get the correct answer.

    I do not grade my homework on correctness. Students only need to show me effort that they honestly attempted each problem for full credit. But it’s way quicker for students to simply upload my homework pdf to chatgpt and copy down the output than give it their own attempt.

    Of course, doing this results in poor exam performance. Anecdotally, my exams from my recent fall semester were the lowest they’ve ever been. I put two problems on my final that directly came from from my homework, one of them being the problem that made me realize roughly 75% of my class was chatgpt’ing all the homework as chatgpt isn’t super great at reading angles from figures, and it’s like these students had never even seen a problem like it before.

    I’m not completely against the use of AI for my homework. It could be like a tutor that students ask questions to when stuck. But unfortunately that takes more effort than simply typing “solve problems 1 through 5, showing all steps, from this document” into chatgpt.