Simple Machines B/Compound Machines C

[bernard]

I submitted an FAQ about hooks and they responded via email. Here is what they said:

Are hooks that slide along each lever and are used to attach masses allowed? (section: 3 / paragraph: e / sub-paragraph: / line: 1-2)
Yes

[slytherin]

I submitted an FAQ about hooks and they responded via email. Here is what they said:

Are hooks that slide along each lever and are used to attach masses allowed? (section: 3 / paragraph: e / sub-paragraph: / line: 1-2)
Yes

Thanks

[ScienceOlympian]

Hey guys

I don't participate in this event; however, some of my close friends are doing it. Our Regional competition is in less than one week, and we at least want to do mediocre (or not utterly fail and/or get last place) on this event. Studying will not be too hard of a challenge for them, but I need advice building the levers (as I will help them with the event).

Unfortunately, they were put on this event at the last minute and never really had time to build the levers (or they procrastinated), so in the 5 days until the Regional comp, they have to create the compound lever -.-
Any advice on making a lever with the cheapest materials and the least amount of time for Division C? We at least don't want our team to utterly fail at the event (like we will do in every build event...no one built anything).

I saw some amazing examples, but we will not be able to create one of them in the amount of time we have (plus, we don't have enough materials). I know last year, for Div B, my team created an extremely simple lever with a meterstick and a cup as a fulcrum, but I don't know if that will work with two levers. Any advice on levers that will get them through the competition?
I don't even think we have sticks for the levers -.-


I really hate the predicament we're in, but hey, it wasn't my fault. :/


Also, I really don't understand how the testing works. When the ES gives the masses to the competitors, how do they attach the masses to the lever? I know there will be loop of a material on the mass, but would they just put the lever through the loops or something? -.- Gosh, I don't know anything about this event, although I've been researching about it for like 3 hours :/

Also, to find the ratio, how would you find the distances that you plug into a formula? For example, would you adjust the masses so that your levers were at equillibrium, then calculate the distances (e.g. of the masses to the fulcrum) in order to find the ratio? I'm clueless, and no one else at my school knows anything about this event >.<

Well, that's a lot of questions. Sorry if I sound like I don't know anything. My school is probably going to fail (this is only our 2nd year :/). The middle school is so much better than us
I'm sorry if I sound extremely ignorant and for any inconveniences that you may have had from reading or replying to this horrible, clueless post. I apologize.

[finagle29]

Any advice on making a lever with the cheapest materials and the least amount of time for Division C?

two metersticks attached at their ends works great. The trick is in the fulcrums. Binder clips might be a cheap way to get them to rotate if you put a bar through the holes in the binder clip.
general design:

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Also, I really don't understand how the testing works. When the ES gives the masses to the competitors, how do they attach the masses to the lever? I know there will be loop of a material on the mass, but would they just put the lever through the loops or something?

Precisely. The lever goes through the loops on most designs, although some teams have screws drilled onto their levers for quick attachment. This design is rather limiting, though as you are unlikely to be able to precisely balance your levers if you can't make fine adjustments.

Also, to find the ratio, how would you find the distances that you plug into a formula? For example, would you adjust the masses so that your levers were at equillibrium, then calculate the distances (e.g. of the masses to the fulcrum) in order to find the ratio? I'm clueless, and no one else at my school knows anything about this event >.<

The basic idea is to get your levers in equilibrium and then use the fact that the net torque is 0 to calculate the ratio of two masses. Its also possible to place all 3 masses on the device at once and move two masses until it balanced again and then with some clever algebra calculating three ratios at once.

[ScienceOlympian]

Any advice on making a lever with the cheapest materials and the least amount of time for Division C?

two metersticks attached at their ends works great. The trick is in the fulcrums. Binder clips might be a cheap way to get them to rotate if you put a bar through the holes in the binder clip.
general design:

Code: Select all

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Thank you so much!

Would the metersticks be connected with string?
Also, would the metersticks just lay on the fulcrums? There isn't a way to secure the sticks onto the fulcrum, right?

Also, what would you use to elevate the levers? Could I use anything to elevate it? Just double-checking.
OMG I sound so annoying. :/

[blindmewithscience]

Thank you so much!

Would the metersticks be connected with string?
Also, would the metersticks just lay on the fulcrums? There isn't a way to secure the sticks onto the fulcrum, right?

Also, what would you use to elevate the levers? Could I use anything to elevate it? Just double-checking.
OMG I sound so annoying. :/

Given you time constraint, I'd definitely suggest string. If you have a bar going through a binder clip going through a hole in the meterstick, I think that should secure it enough. In addition, you could attack these binder clips to some blocks of wood to make it more stable.

[blindmewithscience]

So, we're nearing competition date for a lot of state competitions. What are your guys' average scores on the lab portion? How accurate are you and how fast are you getting your ratios in?
My team usually has max 3% error and done in under 2 minutes, for a score of around 44.

[mjcox2000]

So, we're nearing competition date for a lot of state competitions. What are your guys' average scores on the lab portion? How accurate are you and how fast are you getting your ratios in?
My team usually has max 3% error and done in under 2 minutes, for a score of around 44.

My team is almost always less than 1-2% error, and we're typically take ~35-40 seconds.

[Unome]

So, we're nearing competition date for a lot of state competitions. What are your guys' average scores on the lab portion? How accurate are you and how fast are you getting your ratios in?
My team usually has max 3% error and done in under 2 minutes, for a score of around 44.

My team is almost always less than 1-2% error, and we're typically take ~35-40 seconds.

Mine is about the same, slightly slower (40-45)

[slytherin]

So, we're nearing competition date for a lot of state competitions. What are your guys' average scores on the lab portion? How accurate are you and how fast are you getting your ratios in?
My team usually has max 3% error and done in under 2 minutes, for a score of around 44.

My team is almost always less than 1-2% error, and we're typically take ~35-40 seconds.

Mine is about the same, slightly slower (40-45)

Same with mine, our last competition I think we got a 46 I think..
And, does anyone know what the Kansas State competition usually looks like? Or any state competition?