Comments on: In Which I Fail Physics 101… http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/ Wed, 07 Jan 2009 22:39:50 +0000 http://wordpress.org/?v=2.5.1 By: Bob http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-104286 Bob Sun, 13 Jan 2008 18:07:26 +0000 http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-104286 It is nice to know that we all have been haunted by the chapters in Physics 101 that we all thought we resolved fully and casted them aside, thinking they weren't going to come back to annoy us anymore. Even the pulleys should have been told that they have the property of being frictionless. It is nice to know that we all have been haunted by the chapters in Physics 101 that we all thought we resolved fully and casted them aside, thinking they weren’t going to come back to annoy us anymore.
Even the pulleys should have been told that they have the property of being frictionless.

]]> By: Tommy http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103745 Tommy Fri, 11 Jan 2008 02:52:14 +0000 http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103745 Ahhhh, you should have informed those lines they were supposed to be massless. Annoying real world effects :). Ahhhh, you should have informed those lines they were supposed to be massless. Annoying real world effects :).

]]> By: Clifford http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103699 Clifford Thu, 10 Jan 2008 21:21:03 +0000 http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103699 EJ -yes. That was the flaw. Two lines passing over a pulley mounted on the beam to the left. The line was anchored on the beam (to the right), instead of to the ceiling, so only one line. (Oh, silly me. Tommy, others:- I blotted out a bit more than I intended on the first picture. Upper right there is a ceiling anchored pulley that turns the rope down to the beam.) Cheers, -cvj EJ -yes. That was the flaw. Two lines passing over a pulley mounted on the beam to the left. The line was anchored on the beam (to the right), instead of to the ceiling, so only one line.

(Oh, silly me. Tommy, others:- I blotted out a bit more than I intended on the first picture. Upper right there is a ceiling anchored pulley that turns the rope down to the beam.)

Cheers,

-cvj

]]> By: EJ http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103698 EJ Thu, 10 Jan 2008 21:16:40 +0000 http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103698 Did you initially have two lines on the left, but only one dropping down on the right? Did you initially have two lines on the left, but only one dropping down on the right?

]]> By: Eric http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103686 Eric Thu, 10 Jan 2008 20:05:50 +0000 http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103686 Ahh, sweet mechanical advantage. That's the kind of thing that would trip me up as well. It's difficult to spot here because the line on the left blends in with the tree; when I first looked at it, I thought that the rope was just attached by eye hooks to both ends of the beam. Ahh, sweet mechanical advantage. That’s the kind of thing that would trip me up as well. It’s difficult to spot here because the line on the left blends in with the tree; when I first looked at it, I thought that the rope was just attached by eye hooks to both ends of the beam.

]]> By: Tommy http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103682 Tommy Thu, 10 Jan 2008 19:58:08 +0000 http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103682 Um, is there no pulley on the right in the first picture? Hard to see. Um, is there no pulley on the right in the first picture? Hard to see.

]]> By: Paul Clapham http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103673 Paul Clapham Thu, 10 Jan 2008 19:30:51 +0000 http://asymptotia.com/2008/01/10/in-which-i-fail-physics-101/#comment-103673 Ah, yes, real life versus classroom. I spent two years as a physics major at university but I was still baffled recently when I couldn't siphon water out of my garden pond into a bucket sitting next to the pond. And I learned about conservation of angular momentum for the second time when I was playing volleyball. I jumped with my hands above my head and swung them forward to hit the ball. Then to conserve angular momentum, my feet swung forward and I landed in a sitting position. Ah, yes, real life versus classroom. I spent two years as a physics major at university but I was still baffled recently when I couldn’t siphon water out of my garden pond into a bucket sitting next to the pond.

And I learned about conservation of angular momentum for the second time when I was playing volleyball. I jumped with my hands above my head and swung them forward to hit the ball. Then to conserve angular momentum, my feet swung forward and I landed in a sitting position.

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