Lever Tasks

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Lever Tasks

Post by Dark Sabre » November 30th, 2011, 7:30 pm

Topic for discussion.

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Re: Lever Tasks

Post by bri2433 » December 29th, 2011, 3:03 pm

Are there any good examples of 4f? Which two class systems would we combine to get the IMA greater than 5?
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Re: Lever Tasks

Post by mnstrviola » January 15th, 2012, 11:08 am

Image

That's my interpretation of a compound lever. I think it's IMA would be 8.
Please correct me, anyone, if the diagram is incorrect.

I'm not sure how you would be able to use this in the device...

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Re: Lever Tasks

Post by chalker » January 16th, 2012, 8:06 am

mnstrviola wrote:Image

That's my interpretation of a compound lever. I think it's IMA would be 8.
Please correct me, anyone, if the diagram is incorrect.

I'm not sure how you would be able to use this in the device...

That's incorrect. The IMA of the device in the diagram is varying depending on the specific points you look at (yes, one way of looking at it does give an IMA of 8). What's more important though is such a device wouldn't work in practice (assuming you are putting input forces at y and trying to get your output at 8y). The reason is the it's statically balance by the 3y load. The second your input is either smaller or larger than y, the top lever becomes unbalanced and will either fall off or hit the first lever. Another way to look at this is that if you replaced the top fulcrum with a fixed point, the system would continue to work fine, meaning that the 'compound' part is not needed.

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Re: Lever Tasks

Post by chalker » January 16th, 2012, 8:09 am

bri2433 wrote:Are there any good examples of 4f? Which two class systems would we combine to get the IMA greater than 5?

There's a good wikipedia page for this: http://en.wikipedia.org/wiki/Compound_lever

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Re: Lever Tasks

Post by mnstrviola » January 16th, 2012, 8:56 am

Okay, thanks chalker for the explanation.

How about this one found on the wiki page:

http://upload.wikimedia.org/wikipedia/c ... xample.jpg

If we were to use something like this, how would you find the IMA? Also, would the top lever be physically above the other lever or adjacent to if we were to use this design?

EDIT: I'm thinking the IMA is 7.5, based on the equation at the bottom.

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Re: Lever Tasks

Post by chalker » January 16th, 2012, 11:37 am

mnstrviola wrote:Okay, thanks chalker for the explanation.

How about this one found on the wiki page:

http://upload.wikimedia.org/wikipedia/c ... xample.jpg

If we were to use something like this, how would you find the IMA? Also, would the top lever be physically above the other lever or adjacent to if we were to use this design?

EDIT: I'm thinking the IMA is 7.5, based on the equation at the bottom.
The article text to the right of the image explicitly says the IMA is 7.5 The top lever could be moved to be adjacent, which is probably the best way to implement this.

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Re: Lever Tasks

Post by mnstrviola » January 16th, 2012, 11:51 am

Thanks again. This task isn't looking too hard now. I think I will incorporate it into my device.

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Re: Lever Tasks

Post by prelude to death » January 25th, 2012, 11:28 pm

First of all, I know that this isn't the place for official clarifications, but I was wondering what you guys think about the following: Say I had a 1st class lever (sort of like a seesaw), and when I dropped the effort onto the seesaw, the load rises. The load is attached to a 2nd class lever (sort of like a wheelbarrow) by a string. The load then turns into the effort, and the ball - or the load, in this case - would fall out and hit another object, continuing the device. I was just wondering if I made sure the IMA is greater than 5, would that be able to qualify for Task 4f? The only reason I'm not sure is that I'm not sure if that 'utilizes the IMA greater than 5 to cause the next action' or not.

Thanks in advance!
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Re: Lever Tasks

Post by chalker » January 26th, 2012, 4:49 am

prelude to death wrote:First of all, I know that this isn't the place for official clarifications, but I was wondering what you guys think about the following: Say I had a 1st class lever (sort of like a seesaw), and when I dropped the effort onto the seesaw, the load rises. The load is attached to a 2nd class lever (sort of like a wheelbarrow) by a string. The load then turns into the effort, and the ball - or the load, in this case - would fall out and hit another object, continuing the device. I was just wondering if I made sure the IMA is greater than 5, would that be able to qualify for Task 4f? The only reason I'm not sure is that I'm not sure if that 'utilizes the IMA greater than 5 to cause the next action' or not.

Thanks in advance!

The big question is if the input 'effort' on the 1st class lever were applied directly to the string ('effort') of the 2nd class lever, would the final ball or load still be moved? If it would, you wouldn't be utilizing an IMA greater than 5.

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