Pulley Task
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Jim_R
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Pulley Task
Discussion for Pulley task.
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-Nothing\'s gonna get deleted. We\'re gonna be like three little Fonzies here. And what\'s Fonzie like? Come on, what\'s Fonzie like?
-Cool?
-Correctamundo. And that\'s what we\'re gonna be. We\'re gonna be cool. Now, I\'m gonna count to three, and when I count three, you let go of your mouse, and back away from the keyboard. But when you do it, you do it cool. Ready? One... two... three.
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maggymay
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Re: Pulley Task
Gack, what the [blank inserted ok?] is an IMA 3 pulley? (off to go do some endless researching). Hey, if anyone could 'splain it here that would be wonderful 
.
.Re: Pulley Task
Got to love wikipedia. Basically it's the mechanical advantage with regard to the ratio of distances between the effort (weight) and resistance (counterweight).maggymay wrote:Gack, what the [blank inserted ok?] is an IMA 3 pulley? (off to go do some endless researching). Hey, if anyone could 'splain it here that would be wonderful
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Dark Sabre
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Re: Pulley Task
Well, the IMA stands for Ideal Mechanical Advantage. They use this instead of the Actual Mechanical Advantage so that a judge doesn't have to put a force gauge on your system. With some understanding of pulley systems, the IMA can be determined just by inspection.
Wikipedia has a useful illustration of some possible setups:
http://upload.wikimedia.org/wikipedia/c ... ulleys.svg
Like on the first one, the Load is 100N and the Force applied is 100N (and the displacement of the load and force are also equal) so the IMA is 1
The second one, the Force applied is half of the Load (and the displacement of the force is twice that of the load) so the IMA is 2.
etc
There's a lot of ways to set up the pulleys to the same effect, so that #3 there is hardly your only option.
And pencl beats me, curses.
Wikipedia has a useful illustration of some possible setups:
http://upload.wikimedia.org/wikipedia/c ... ulleys.svg
Like on the first one, the Load is 100N and the Force applied is 100N (and the displacement of the load and force are also equal) so the IMA is 1
The second one, the Force applied is half of the Load (and the displacement of the force is twice that of the load) so the IMA is 2.
etc
There's a lot of ways to set up the pulleys to the same effect, so that #3 there is hardly your only option.
And pencl beats me, curses.
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maggymay
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Re: Pulley Task
Just came back in to do some more research...lol pencl & DarkS, you say all that as if a noob will understand itpenclspinner wrote:Got to love wikipedia. Basically it's the mechanical advantage with regard to the ratio of distances between the effort (weight) and resistance (counterweight).maggymay wrote:Gack, what the [blank inserted ok?] is an IMA 3 pulley? (off to go do some endless researching). Hey, if anyone could 'splain it here that would be wonderful
. I'll have to see if I can find some pictures/images that make sense to me 
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DeltaHat
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Re: Pulley Task
The one labeled 3 at http://upload.wikimedia.org/wikipedia/c ... ulleys.svg
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missionimpossible
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Re: Pulley Task
I saw the wikipedia pictures (#3), but are there any other ways to set up this pulley system?
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illusionist
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Re: Pulley Task
Does the pulley system in this video:
http://www.youtube.com/watch?v=MZPvgdBIOhU
Count as an IMA 3 pulley system?
http://www.youtube.com/watch?v=MZPvgdBIOhU
Count as an IMA 3 pulley system?
Re: Pulley Task
Can't to tell from the video. A fixed pulley has an IMA of one. A movable pulley (entire pulley must change location, rotating the sheave in the pulley doesn't count) has an IMA of 2. All the pulleys appear to be fixed, so the IMA would still be 1.
In the above example, there are 3 portions of the string that get shorter as the end of the string (with the arrow) is pulled. For every 3 inches of string that is pulled at the arrow, the weight is raised 1 inch. This makes the IMA = 3.
In the above example, there are 3 portions of the string that get shorter as the end of the string (with the arrow) is pulled. For every 3 inches of string that is pulled at the arrow, the weight is raised 1 inch. This makes the IMA = 3.
Information expressed here is solely the opinion of the author. Any similarity to that of the management or any official instrument is purely coincidental! Doing Science Olympiad since 1987!
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illusionist
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Re: Pulley Task
So the ratio of this pulley system is 3:1 right? In order to raise the mass 15cm, the string would have to be pulled at least 45cm?fleet130 wrote:In the above example, there are 3 portions of the string that get shorter as the end of the string (with the arrow) is pulled. For every 3 inches of string that is pulled at the arrow, the weight is raised 1 inch. This makes the IMA = 3.