• 42 Posts
  • 185 Comments
Joined 2 years ago
cake
Cake day: July 5th, 2023

help-circle
  • The water stays in the bucket because its geometry tilts its axis, keeping the bottom pointing in the direction of the water’s inertia

    I was with you until this line. I spent some time thinking on it and I think I sort of get what you were talking about? Let me see if I can’t explain it back to you. The water and the bucket both want to keep going linearly, which they can’t because of the string. The bucket arcs around, but the inertia of the water keeps going linearly, causing it to press against the bottom of the bucket. If the bucket continues to be driven in circular motion, it’s this momentum that drives the water against the bottom of the bucket? While the side of the bucket drives the water along the circular path?


  • Your third point clarifies some things for me a lot. I seem to have forgotten that acceleration describes a change in direction and/or a change in magnitude of the velocity vector: I recall now in my physics textbooks that objects in non-constant circular motion have a tangential acceleration, and the total acceleration lies somewhere between those, but if the velocity remains constant, then the only acceleration is the centripetal acceleration describing the change in the velocity’s direction.

    However, I still have some questions about points one and two. I understand that things in circular motion want to fly out tangentially away from the center, not radially away. Yet, in so far as I can observe, objects do seem to press outwards radially. In the example with the bucket of water, the water sticks to the bottom of the bucket instead of pressing against the side wall. In another example, that of those carnival rides that spin people around in a saucer (gravitron I think it’s called?), the carmival goers tend to stick to the wall of the ride as though they were being flung out radially, instead of rolling along the edge or something else. I guess it’s this disconnect between what I know is correct (objects fly tangentially to their circular paths) and what I observe (objects stick to the wall radially away from the center).


  • Let me see if I understand this. So the bucket acts on the water, pushing it in a direction, then the bucket’s motion changes, changing the motion of the water, then this repeats ad naseum in a circle. So the bucket is experiencing a centripetal force (tension from the string), but not the water: it’s motion is changing as a result of the bucket pushing on it. So then if the bucket is moving in a counter clockwise direction, the “left” wall of the bucket would be the thing acting on the water. Wouldn’t that cause the water to stick to the left wall of the bucket, not the bottom?

    In regards to your example with the marbles and anti-particles, I understand it in principle, but I’m not quite sure I get how fictitious anti particles relate to fictitious forces. I mean, I think I get it, and I understand what you mean by it not having a universal phenomenon driving the force. I’m just not sure I could explain it back to you.


  • No offense but please don’t insult me like this. I abhor AI and the whole reason I ask this is because I’ve been reading through my old physics text book and got to the part with circular motion. I’ve watched the crash course video on circular motion and have read through physics forums explaining this and the Wikipedia article for this subject and I still don’t understand it.

    I understand where you’re coming from and I know you don’t know me, so it’s a fair assumption considering how much fucking AI there is, and I appreciate you encouraging actual research instead of consulting AI, but damn do I feel insulted.