|
|
|
|
bill413
Aug 10, 2010, 3:20 PM
Post #51 of 140
(7622 views)
Shortcut
Registered: Oct 19, 2004
Posts: 5674
|
dan2see wrote: bill413 wrote: marc801 wrote: dan2see wrote: OK, the guy in the blue shirt is leading, and moving up. The guy with the camera is snapping the action. So where's the belayer? I'd guess that the photographer is the belayer. [img]http://forum.thescubasite.com/happy/happy0065.gif[/img] Sorry, I couldn't resist posting my comment. Recently, some safety reporters on TV were reporting how the highway cops were targeting careless driving habits. One guy was caught combing his hair with one hand, and drinking coffee with the other. "So tell me sir," asked the cop nicely, "who was driving your car?" I'm sure the belayer is managing his left hand on brake, while he snaps his leader. I've done that too. I think my leader was safe at the time, but a one-handed belay is asking for trouble. It really is hard to get good action shots of climbers climbing.
I actually wanted to get a GIF of reeling in a fish.
|
|
|
|
|
dan2see
Aug 10, 2010, 3:22 PM
Post #52 of 140
(7618 views)
Shortcut
Registered: Mar 29, 2006
Posts: 1497
|
 It worked! 
|
|
|
|
|
styndall
Aug 10, 2010, 4:17 PM
Post #53 of 140
(7597 views)
Shortcut
Registered: May 29, 2002
Posts: 2741
|
redlude97 wrote: styndall wrote: redlude97 wrote: styndall wrote: Rudmin wrote: whipper wrote: kjaking wrote: I am surprised that nobody has thought to comment on force multiplication due to pulley effects. The belayer himself is putting more than his body weight on the lower bolt. But I guess he would be pulled upward in a leader fall anyways, so w/e. If the climber had clipped through what the leader is using to anchor himself, there would be big problems in a fall. FAIL There is no pulley effect, a pulley requires a mechanical advantage, there is none. a lot of n00bs on here seem to misunderstand pulley systems. always ask yourself if I pull 1 foot of rope here, how high does the load move....if it is 1 foot, then there is no multiplication of forces, it is a 1 to 1 redirect. Any way it doesnt even matter in this case, as the load is split (albeit poorly) due ot the clove hitch pulling down on the lower bolt. I wouldnt set it up like this, but I wouldn't give a fuck if my partner did...it is not going to fail. Troll or stupid or both. That top bolt is acting as a pulley, same as in American Triangle. Nothing in the ADT acts as a pulley. I would consider multiplication of force a pulley effect Then you should find a dictionary and look up the word pulley. –noun, plural -leys. 1.a wheel, with a grooved rim for carrying a line, that turns in a frame or block and serves to change the direction of or to transmit force, as when one end of the line is pulled to raise a weight at the other end: one of the simple machines. 2.a combination of such wheels in a block, or of such wheels or blocks in a tackle, to increase the force applied. 3.a wheel driven by or driving a belt or the like, used to deliver force to a machine, another belt, etc., at a certain speed and torque. http://dictionary.reference.com/browse/pulley
Did you not notice the requirement of the presence of objects fitting meaning 1 in meaning 2? Because you're clearly literate.
Your definition means that most simple machines are pulleys. You can define pulley that way if you want, but it's not a usual or useful definition.
(This post was edited by styndall on Aug 10, 2010, 4:18 PM)
|
|
|
|
|
redlude97
Aug 10, 2010, 4:27 PM
Post #54 of 140
(7591 views)
Shortcut
Registered: Aug 27, 2008
Posts: 990
|
styndall wrote: redlude97 wrote: styndall wrote: redlude97 wrote: styndall wrote: Rudmin wrote: whipper wrote: kjaking wrote: I am surprised that nobody has thought to comment on force multiplication due to pulley effects. The belayer himself is putting more than his body weight on the lower bolt. But I guess he would be pulled upward in a leader fall anyways, so w/e. If the climber had clipped through what the leader is using to anchor himself, there would be big problems in a fall. FAIL There is no pulley effect, a pulley requires a mechanical advantage, there is none. a lot of n00bs on here seem to misunderstand pulley systems. always ask yourself if I pull 1 foot of rope here, how high does the load move....if it is 1 foot, then there is no multiplication of forces, it is a 1 to 1 redirect. Any way it doesnt even matter in this case, as the load is split (albeit poorly) due ot the clove hitch pulling down on the lower bolt. I wouldnt set it up like this, but I wouldn't give a fuck if my partner did...it is not going to fail. Troll or stupid or both. That top bolt is acting as a pulley, same as in American Triangle. Nothing in the ADT acts as a pulley. I would consider multiplication of force a pulley effect Then you should find a dictionary and look up the word pulley. –noun, plural -leys. 1.a wheel, with a grooved rim for carrying a line, that turns in a frame or block and serves to change the direction of or to transmit force, as when one end of the line is pulled to raise a weight at the other end: one of the simple machines. 2.a combination of such wheels in a block, or of such wheels or blocks in a tackle, to increase the force applied. 3.a wheel driven by or driving a belt or the like, used to deliver force to a machine, another belt, etc., at a certain speed and torque. http://dictionary.reference.com/browse/pulleyDid you not notice the requirement of the presence of objects fitting meaning 1 in meaning 2? Because you're clearly literate. Your definition means that most simple machines are pulleys. You can define pulley that way if you want, but it's not a usual or useful definition.
|
|
|
|
|
styndall
Aug 10, 2010, 4:35 PM
Post #56 of 140
(7581 views)
Shortcut
Registered: May 29, 2002
Posts: 2741
|
redlude97 wrote: So are you saying carabiners used in a haul system are not acting as pulleys? Have you ever set up a slackline? If you don't think the carabiners are acting as pulleys in that case then yes, we won't agree on this topic, but almost everyone else will consider it a pulley system. The wheel is there to reduce friction yes, but no totally eliminate it. The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction).
We're talking about the ADT, which doesn't have any pulley components. Of course a slackline or a haul system has pulleys. The ADT is effectively a single piece of line strung between two points.
|
|
|
|
|
patmay81
Aug 10, 2010, 4:36 PM
Post #57 of 140
(7580 views)
Shortcut
Registered: Aug 3, 2006
Posts: 1081
|
I'd probably climb on it, but I certainly would not have constructed it that way.
|
|
|
|
|
redlude97
Aug 10, 2010, 4:39 PM
Post #58 of 140
(7578 views)
Shortcut
Registered: Aug 27, 2008
Posts: 990
|
styndall wrote: redlude97 wrote: So are you saying carabiners used in a haul system are not acting as pulleys? Have you ever set up a slackline? If you don't think the carabiners are acting as pulleys in that case then yes, we won't agree on this topic, but almost everyone else will consider it a pulley system. The wheel is there to reduce friction yes, but no totally eliminate it. The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction). We're talking about the ADT, which doesn't have any pulley components. Of course a slackline or a haul system has pulleys. The ADT is effectively a single piece of line strung between two points.
|
|
|
|
|
jt512
Aug 10, 2010, 5:51 PM
Post #59 of 140
(7546 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
redlude97 wrote: The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction).
The carabiner is indeed acting as a pulley with friction, but a single carabiner or pulley attached to a fixed position provides no mechanical advantage.
Jay
|
|
|
|
|
redlude97
Aug 10, 2010, 5:57 PM
Post #60 of 140
(7538 views)
Shortcut
Registered: Aug 27, 2008
Posts: 990
|
jt512 wrote: redlude97 wrote: The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction). The carabiner is indeed acting as a pulley with friction, but a single carabiner or pulley attached to a fixed position provides no mechanical advantage. Jay
Edited to add: I shouldn't have used mechanical advantage, but rather force multiplication as I has previously used. See post below about engineers misusing terms 
(This post was edited by redlude97 on Aug 10, 2010, 6:06 PM)
|
|
|
|
|
milesenoell
Aug 10, 2010, 6:02 PM
Post #61 of 140
(7537 views)
Shortcut
Registered: Sep 19, 2006
Posts: 1156
|
jt512 wrote: redlude97 wrote: The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction). The carabiner is indeed acting as a pulley with friction, but a single carabiner or pulley attached to a fixed position provides no mechanical advantage. Jay
I think this was all about whether the top piece takes more than the load on the rope, which it does, but everybody thinks they know enough to get all specific and end up using technical terms that they aren't particularly good with.
See if we could just get rid of all the engineers around here we might be able to misuse these terms in peace. Don't go confusing me with the facts again.
|
|
|
|
|
milesenoell
Aug 10, 2010, 6:12 PM
Post #62 of 140
(7531 views)
Shortcut
Registered: Sep 19, 2006
Posts: 1156
|
redlude97 wrote: jt512 wrote: redlude97 wrote: The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction). The carabiner is indeed acting as a pulley with friction, but a single carabiner or pulley attached to a fixed position provides no mechanical advantage. Jay The force felt by the fixed pulley/anchor is twice the force applied. That is what I meant by mechanical advantage. If you didn't fix the anchor/pulley and instead hung your object from the biner/pulley, it would move half the distance and require half the force compared to pulling it directly up.
Uh, no.
Whether I pull rope from the top, right at the anchor or from the bottom as the belayer makes no difference. 1 foot for me is 1 foot for the climber. The only way it would change is if I were to pull up on the anchor itself, and since that has never been a situation we were looking at, I consider the point to be moot.
|
|
|
|
|
redlude97
Aug 10, 2010, 6:23 PM
Post #63 of 140
(7523 views)
Shortcut
Registered: Aug 27, 2008
Posts: 990
|
milesenoell wrote: redlude97 wrote: jt512 wrote: redlude97 wrote: The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction). The carabiner is indeed acting as a pulley with friction, but a single carabiner or pulley attached to a fixed position provides no mechanical advantage. Jay The force felt by the fixed pulley/anchor is twice the force applied. That is what I meant by mechanical advantage. If you didn't fix the anchor/pulley and instead hung your object from the biner/pulley, it would move half the distance and require half the force compared to pulling it directly up. Uh, no. Whether I pull rope from the top, right at the anchor or from the bottom as the belayer makes no difference. 1 foot for me is 1 foot for the climber. The only way it would change is if I were to pull up on the anchor itself, and since that has never been a situation we were looking at, I consider the point to be moot.
The reason this applies to the ADT is the doubling of the force felt by the anchor/biner/pulley(minus friction and angles).
|
|
|
|
|
jt512
Aug 10, 2010, 6:34 PM
Post #64 of 140
(7514 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
redlude97 wrote: milesenoell wrote: redlude97 wrote: jt512 wrote: redlude97 wrote: The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction). The carabiner is indeed acting as a pulley with friction, but a single carabiner or pulley attached to a fixed position provides no mechanical advantage. Jay The force felt by the fixed pulley/anchor is twice the force applied. That is what I meant by mechanical advantage. If you didn't fix the anchor/pulley and instead hung your object from the biner/pulley, it would move half the distance and require half the force compared to pulling it directly up. Uh, no. Whether I pull rope from the top, right at the anchor or from the bottom as the belayer makes no difference. 1 foot for me is 1 foot for the climber. The only way it would change is if I were to pull up on the anchor itself, and since that has never been a situation we were looking at, I consider the point to be moot. Maybe I wasn't clear in what I was explaining. Yes the distance you pull on either end of the rope is the same. In that sense it is a redirect. The way a single pulley can have mechanical advantage is to hang the object to be moved from the pulley itself. In that case the force is 1/2 and the distance moved is 1/2. Like this: The reason this applies to the ADT is the doubling of the force felt by the anchor/biner/pulley(minus friction and angles).
No, that doesn't apply to an American Triangle (AT) at all. A pulley attached to the load affords a mechanical of 2. In an AT the "pulleys" aren't attached to the load but to fixed positions, so there is no mechanical advantage. Rather, for any angle at the bottom of the triangle, there is a greater force on the bolts due to the horizontal arm of the triangle, relative to a V-shaped anchor with same angle.
Jay
(This post was edited by jt512 on Aug 10, 2010, 6:36 PM)
|
|
|
|
|
redlude97
Aug 10, 2010, 6:58 PM
Post #65 of 140
(7495 views)
Shortcut
Registered: Aug 27, 2008
Posts: 990
|
jt512 wrote: redlude97 wrote: milesenoell wrote: redlude97 wrote: jt512 wrote: redlude97 wrote: The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction). The carabiner is indeed acting as a pulley with friction, but a single carabiner or pulley attached to a fixed position provides no mechanical advantage. Jay The force felt by the fixed pulley/anchor is twice the force applied. That is what I meant by mechanical advantage. If you didn't fix the anchor/pulley and instead hung your object from the biner/pulley, it would move half the distance and require half the force compared to pulling it directly up. Uh, no. Whether I pull rope from the top, right at the anchor or from the bottom as the belayer makes no difference. 1 foot for me is 1 foot for the climber. The only way it would change is if I were to pull up on the anchor itself, and since that has never been a situation we were looking at, I consider the point to be moot. Maybe I wasn't clear in what I was explaining. Yes the distance you pull on either end of the rope is the same. In that sense it is a redirect. The way a single pulley can have mechanical advantage is to hang the object to be moved from the pulley itself. In that case the force is 1/2 and the distance moved is 1/2. Like this: [image]http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Pulley1.svg/399px-Pulley1.svg.png[/image] The reason this applies to the ADT is the doubling of the force felt by the anchor/biner/pulley(minus friction and angles). No, that doesn't apply to an American Triangle (AT) at all. A pulley attached to the load affords a mechanical of 2. In an AT the "pulleys" aren't attached to the load but to fixed positions, so there is no mechanical advantage. Rather, for any angle at the bottom of the triangle, there is a greater force on the bolts due to the horizontal arm of the triangle, relative to a V-shaped anchor with same angle. Jay
|
|
|
|
|
styndall
Aug 10, 2010, 7:03 PM
Post #66 of 140
(7489 views)
Shortcut
Registered: May 29, 2002
Posts: 2741
|
redlude97 wrote: jt512 wrote: redlude97 wrote: milesenoell wrote: redlude97 wrote: jt512 wrote: redlude97 wrote: The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction). The carabiner is indeed acting as a pulley with friction, but a single carabiner or pulley attached to a fixed position provides no mechanical advantage. Jay The force felt by the fixed pulley/anchor is twice the force applied. That is what I meant by mechanical advantage. If you didn't fix the anchor/pulley and instead hung your object from the biner/pulley, it would move half the distance and require half the force compared to pulling it directly up. Uh, no. Whether I pull rope from the top, right at the anchor or from the bottom as the belayer makes no difference. 1 foot for me is 1 foot for the climber. The only way it would change is if I were to pull up on the anchor itself, and since that has never been a situation we were looking at, I consider the point to be moot. Maybe I wasn't clear in what I was explaining. Yes the distance you pull on either end of the rope is the same. In that sense it is a redirect. The way a single pulley can have mechanical advantage is to hang the object to be moved from the pulley itself. In that case the force is 1/2 and the distance moved is 1/2. Like this: [image]http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Pulley1.svg/399px-Pulley1.svg.png[/image] The reason this applies to the ADT is the doubling of the force felt by the anchor/biner/pulley(minus friction and angles). No, that doesn't apply to an American Triangle (AT) at all. A pulley attached to the load affords a mechanical of 2. In an AT the "pulleys" aren't attached to the load but to fixed positions, so there is no mechanical advantage. Rather, for any angle at the bottom of the triangle, there is a greater force on the bolts due to the horizontal arm of the triangle, relative to a V-shaped anchor with same angle. Jay Yes no mechanical advantage. I shouldn't have ever used that term. Force mutliplication, even on a fixed point at a redirect is by definition a pulley effect though.
Argh. Not all force multiplication falls under 'pulley effect.' I can make a lever with a bit of bar stock. Does my lever use the pulley effect?
|
|
|
|
|
Rudmin
Aug 10, 2010, 7:06 PM
Post #67 of 140
(7485 views)
Shortcut
Registered: Mar 29, 2009
Posts: 606
|
jt512 wrote: redlude97 wrote: milesenoell wrote: redlude97 wrote: jt512 wrote: redlude97 wrote: The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction). The carabiner is indeed acting as a pulley with friction, but a single carabiner or pulley attached to a fixed position provides no mechanical advantage. Jay The force felt by the fixed pulley/anchor is twice the force applied. That is what I meant by mechanical advantage. If you didn't fix the anchor/pulley and instead hung your object from the biner/pulley, it would move half the distance and require half the force compared to pulling it directly up. Uh, no. Whether I pull rope from the top, right at the anchor or from the bottom as the belayer makes no difference. 1 foot for me is 1 foot for the climber. The only way it would change is if I were to pull up on the anchor itself, and since that has never been a situation we were looking at, I consider the point to be moot. Maybe I wasn't clear in what I was explaining. Yes the distance you pull on either end of the rope is the same. In that sense it is a redirect. The way a single pulley can have mechanical advantage is to hang the object to be moved from the pulley itself. In that case the force is 1/2 and the distance moved is 1/2. Like this: [image]http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Pulley1.svg/399px-Pulley1.svg.png[/image] The reason this applies to the ADT is the doubling of the force felt by the anchor/biner/pulley(minus friction and angles). No, that doesn't apply to an American Triangle (AT) at all. A pulley attached to the load affords a mechanical of 2. In an AT the "pulleys" aren't attached to the load but to fixed positions, so there is no mechanical advantage. Rather, for any angle at the bottom of the triangle, there is a greater force on the bolts due to the horizontal arm of the triangle, relative to a V-shaped anchor with same angle. Jay
You certainly do have a mechanical advantage if your goal is to break the bolts. A bolt that fails at 10 kN will only need about 6 or 7 kN or so of pull applied as tension in the webbing to break it. The extra force is provided by mechanical advantage.
You are just confusing mechanical advantage within the anchor with mechanical advantage in the climbing rope. A force multiplier/lever/mechanical advantage/pulley system are all the same thing. They allow a small force to produce a large force somewhere else.
|
|
|
|
|
jt512
Aug 10, 2010, 7:11 PM
Post #68 of 140
(7483 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
redlude97 wrote: Yes no mechanical advantage. I shouldn't have ever used that term. Force mutliplication, even on a fixed point at a redirect is by definition a pulley effect though.
As far as I am aware nothing is "by definition" a pulley effect, because, as far as I am aware, "pulley effect" is not a real term in physics or engineering. I've never seen the term used by anyone other than climbers on the internet.
Jay
(This post was edited by jt512 on Aug 10, 2010, 7:12 PM)
|
|
|
|
|
Toast_in_the_Machine
Aug 10, 2010, 7:27 PM
Post #69 of 140
(7468 views)
Shortcut
Registered: Sep 12, 2008
Posts: 5208
|
jt512 wrote: redlude97 wrote: Yes no mechanical advantage. I shouldn't have ever used that term. Force mutliplication, even on a fixed point at a redirect is by definition a pulley effect though. As far as I am aware nothing is "by definition" a pulley effect, because, as far as I am aware, "pulley effect" is not a real term in physics or engineering. I've never seen the term used by anyone other than climbers on the internet. Jay
Jay - prepare to be amazed:
http://pubs.acs.org/...bs/10.1021/ma061037s
To be honest, google results 1-5 were climbing and A2 injuries.
|
|
|
|
|
marc801
Aug 10, 2010, 7:34 PM
Post #70 of 140
(7464 views)
Shortcut
Registered: Aug 1, 2005
Posts: 2806
|
Japanese chemists translated into English. Pffft. What do they know.
|
|
|
|
|
redlude97
Aug 10, 2010, 8:18 PM
Post #71 of 140
(7445 views)
Shortcut
Registered: Aug 27, 2008
Posts: 990
|
styndall wrote: redlude97 wrote: jt512 wrote: redlude97 wrote: milesenoell wrote: redlude97 wrote: jt512 wrote: redlude97 wrote: The carabiner works in the same way just with more friction. To say one is a pulley and the other is not when rigged in the same way IMO doesn't make any sense. They still give you the same mechanical advantage(minus the loss to friction). The carabiner is indeed acting as a pulley with friction, but a single carabiner or pulley attached to a fixed position provides no mechanical advantage. Jay The force felt by the fixed pulley/anchor is twice the force applied. That is what I meant by mechanical advantage. If you didn't fix the anchor/pulley and instead hung your object from the biner/pulley, it would move half the distance and require half the force compared to pulling it directly up. Uh, no. Whether I pull rope from the top, right at the anchor or from the bottom as the belayer makes no difference. 1 foot for me is 1 foot for the climber. The only way it would change is if I were to pull up on the anchor itself, and since that has never been a situation we were looking at, I consider the point to be moot. Maybe I wasn't clear in what I was explaining. Yes the distance you pull on either end of the rope is the same. In that sense it is a redirect. The way a single pulley can have mechanical advantage is to hang the object to be moved from the pulley itself. In that case the force is 1/2 and the distance moved is 1/2. Like this: [image]http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Pulley1.svg/399px-Pulley1.svg.png[/image] The reason this applies to the ADT is the doubling of the force felt by the anchor/biner/pulley(minus friction and angles). No, that doesn't apply to an American Triangle (AT) at all. A pulley attached to the load affords a mechanical of 2. In an AT the "pulleys" aren't attached to the load but to fixed positions, so there is no mechanical advantage. Rather, for any angle at the bottom of the triangle, there is a greater force on the bolts due to the horizontal arm of the triangle, relative to a V-shaped anchor with same angle. Jay Yes no mechanical advantage. I shouldn't have ever used that term. Force mutliplication, even on a fixed point at a redirect is by definition a pulley effect though. Argh. Not all force multiplication falls under 'pulley effect.' I can make a lever with a bit of bar stock. Does my lever use the pulley effect?
(This post was edited by redlude97 on Aug 10, 2010, 8:21 PM)
|
|
Attachments:
|
ADT Pulley.jpg
(13.8 KB)
|
|
|
|
|
jt512
Aug 10, 2010, 8:20 PM
Post #72 of 140
(7441 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
Toast_in_the_Machine wrote: jt512 wrote: redlude97 wrote: Yes no mechanical advantage. I shouldn't have ever used that term. Force mutliplication, even on a fixed point at a redirect is by definition a pulley effect though. As far as I am aware nothing is "by definition" a pulley effect, because, as far as I am aware, "pulley effect" is not a real term in physics or engineering. I've never seen the term used by anyone other than climbers on the internet. Jay Jay - prepare to be amazed: http://pubs.acs.org/...bs/10.1021/ma061037s
I'm not even remotely amazed. They are not using the term "pulley effect" to mean whatever it is that climbers think it means.
The linked article wrote: The SR gels have a unique characteristic called the “pulley effect” that the cross-links made of α-cyclodextrin molecules in a figure-eight shape can slide along the polymer chain.
Jay
|
|
|
|
|
jt512
Aug 10, 2010, 8:23 PM
Post #73 of 140
(7435 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
redlude97 wrote: Yes you are right I shouldn't have been so general in my statement. But the multiplication of force in an ADT on one of the anchor points is a pulley effect.
If you say so. Like I said, no physics reference that I have ever seen defines or refers to such a "pulley effect."
Jay
|
|
|
|
|
redlude97
Aug 10, 2010, 8:30 PM
Post #74 of 140
(7426 views)
Shortcut
Registered: Aug 27, 2008
Posts: 990
|
jt512 wrote: redlude97 wrote: Yes you are right I shouldn't have been so general in my statement. But the multiplication of force in an ADT on one of the anchor points is a pulley effect. If you say so. Like I said, no physics reference that I have ever seen defines or refers to such a "pulley effect." Jay
|
|
|
|
|
Toast_in_the_Machine
Aug 10, 2010, 8:31 PM
Post #75 of 140
(7425 views)
Shortcut
Registered: Sep 12, 2008
Posts: 5208
|
jt512 wrote: Toast_in_the_Machine wrote: jt512 wrote: redlude97 wrote: Yes no mechanical advantage. I shouldn't have ever used that term. Force mutliplication, even on a fixed point at a redirect is by definition a pulley effect though. As far as I am aware nothing is "by definition" a pulley effect, because, as far as I am aware, "pulley effect" is not a real term in physics or engineering. I've never seen the term used by anyone other than climbers on the internet. Jay Jay - prepare to be amazed: http://pubs.acs.org/...bs/10.1021/ma061037s I'm not even remotely amazed. They are not using the term "pulley effect" to mean whatever it is that climbers think it means. The linked article wrote: The SR gels have a unique characteristic called the “pulley effect” that the cross-links made of α-cyclodextrin molecules in a figure-eight shape can slide along the polymer chain. Jay
Quit shooting at everything that moves Dick Cheney.
I was helping your point. "Pully effect" only shows up in translated chemical articles and climbing sites.
|
|
|
|
|
|
|
|
|
