Simple Machines B/Compound Machines C

helicpters_rule
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Re: Simple Machines B/Compound Machines C

Postby helicpters_rule » November 26th, 2013, 8:16 pm

I'm in division B (simple machines). Does anyone have examples of questions on the test or how exactly to find out the mass of the object they provide :?: I'm new.
(distance to known mass/distance to unknown mass) x known mass = unknown mass.

mnstrviola
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Re: Simple Machines B/Compound Machines C

Postby mnstrviola » November 26th, 2013, 8:45 pm

I'm in division B (simple machines). Does anyone have examples of questions on the test or how exactly to find out the mass of the object they provide :?: I'm new.
(distance to known mass/distance to unknown mass) x known mass = unknown mass.
I don't think that formula will work, because there will be 2 levers and you have to calculate the mass based on both of the levers' different MAs. So the known mass will have a different output into the lever that has the unknown. You should try to design your lever to fit the range of masses given in the rules.
For compound machines, the device is a class 1 lever with the 'load' attached to the 'effort' of a class 2 lever. Wikipedia has a good overview of the various types of levers: http://en.wikipedia.org/wiki/Lever

helicpters_rule
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Re: Simple Machines B/Compound Machines C

Postby helicpters_rule » November 27th, 2013, 5:07 am

I'm in division B (simple machines). Does anyone have examples of questions on the test or how exactly to find out the mass of the object they provide :?: I'm new.
(distance to known mass/distance to unknown mass) x known mass = unknown mass.
I don't think that formula will work, because there will be 2 levers and you have to calculate the mass based on both of the levers' different MAs. So the known mass will have a different output into the lever that has the unknown. You should try to design your lever to fit the range of masses given in the rules.
For compound machines, the device is a class 1 lever with the 'load' attached to the 'effort' of a class 2 lever. Wikipedia has a good overview of the various types of levers: http://en.wikipedia.org/wiki/Lever
Ya mnstrviola is right my formula only works for simple machines but im in simple machines and it is what I use.

helicpters_rule
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Re: Simple Machines B/Compound Machines C

Postby helicpters_rule » November 28th, 2013, 7:32 am

A question for those who may know more about this topic than I do: if questions are limited to static equilibrium per 4.a.iii, how could they involve kinetic energy as suggested in 4.a.ii?
I don't know exactly but maybe you have to do calculations for efficiency but you don't have to solve more complex problems for the with efficiency. I am guessing that your are referring to efficiency. So in maybe a simpler terms static equilibrium and calculations are 2 different sections that may have nothing to do with each other. This is my guess if someone doesn't agree please disagree. This is very confusing and maybe they just mad a mistake.

helicpters_rule
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Re: Simple Machines B/Compound Machines C

Postby helicpters_rule » November 28th, 2013, 7:36 am

i don't what to learn this wrong can someone show me what 2 double pulleys look like.

helicpters_rule
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Re: Simple Machines B/Compound Machines C

Postby helicpters_rule » November 28th, 2013, 12:50 pm

How would one find the ideal mechanical advantage of a wedge? The only reason I am asking this is because I used to believe it was the side length divided by thickness, according to http://iqa.evergreenps.org/science/phy_science/ma.html, but I recently saw another source that claimed it was the depth of penetration divided by thickness of wedge, according to http://hyperphysics.phy-astr.gsu.edu/hb ... cline.html. Which is correct? Please help!
I did the math and it is depth of penetration divided by the thickness if you want to see my math ask and ill try to post it.

JeffMan
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Re: Simple Machines B/Compound Machines C

Postby JeffMan » December 13th, 2013, 12:08 pm

For Compound Machines is there any Formulas or equations that I would or anybody would not think about or not go into great detail?

Sciolapedia
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Re: Simple Machines B/Compound Machines C

Postby Sciolapedia » December 13th, 2013, 2:48 pm

Can someone help me on where to get information for the history part of the test. Aside from the Wikipedia paragraph and a couple undescriptive google sites, I have nothing. Thanks

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Re: Simple Machines B/Compound Machines C

Postby Tantalum » December 16th, 2013, 8:49 am

Ok this is my first year in compound machines and my partner and I have no idea what we are suposed to build! I know it is supposed to be a class 1 lever connected directly in series to a class 2 lever but I do not know what it is supposed to look like. If someone could please give me a link to some pics that would be very helpful. Thanks!

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Re: Simple Machines B/Compound Machines C

Postby hscmom » December 17th, 2013, 7:45 pm

Ok this is my first year in compound machines and my partner and I have no idea what we are suposed to build! I know it is supposed to be a class 1 lever connected directly in series to a class 2 lever but I do not know what it is supposed to look like. If someone could please give me a link to some pics that would be very helpful. Thanks!
How we started with this is to make sure we knew what a 1st class lever looks like and what a 2nd class lever looks like. Then we sketched and sketched, realizing that things can be stacked vertically, connected more or less horizontally, even at a 90 degree angle. It just has to fit the dimensions in the rules... You won't find many photos on the internet simply because this is a new event and what the rules are asking for is not a common project that kids are asked to do (on the other hand, you'll find millions of photos of baking soda and vinegar "volcanoes"). What you will find are photos of different balances, which is helpful for stealing design ideas... Start looking for design elements you tend to see in scales.

Oh, and it's everyone's first year in compound machines! :)
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