Machines B/C

[bergerbaby]

Does anybody have an example of the graphs for this event
thanks

[TheMysteriousMapMan]

I am creating my notes and looking at practice tests as well to see the format and things that are important, and the practice test had some measurement conversions. Which measurement conversions (kg to N, cm to m, etc.) should I know>

DISCLAIMER: I'm not doing this event, but I did Thermo in the past which often dealt quite a bit with unit conversion.

I would know how to convert between all metric units used in Machines and their imperial equivalents (e.g. kg to lbs, ft. to m), since test writers often like to throw you those as an additional layer of complexity. In addition, sometimes weird archaic units are sometimes thrown on tests, so having that sort of thing in your binder just in case definitely won't hurt. As for the ones you mentioned, knowing the metric prefixes (milli, centi, deci....) is definitely good, since some units, like Newtons, are based on a particular metric unit (kg). As for kg to N, those are measures of different things. kg is mass, whereas N is force, and therefore weight (force of gravity on an object). Thus, to "convert" from kg to N, you use Newton's second law (F=ma) and multiply your mass by the acceleration of the object (in the case of weight, by the gravitational acceleration of ~9.8 m/s/s).

Hope this helps!

[T&J101]

My boi Sahil wants some pics of some Machine ideas for division C.

[Fallsbury]

I just started focusing on machines and I'm kinda confused on what the best way to build the lever is. Would you just have a lever hanging off a string or something like that? And how would you attach the weights to the lever?

The weights will come equipped with loops on top, so they could be attached by hooks on your lever, or just put the loop on the lever. Hanging off a string might not be a good idea, as the lever would rotate as the weights are adjusted, but if you can find a way to minimize that, it might work. Otherwise, any way of attaching a lever to a low-friction fulcrum would work, such as mounting a ball bearing to a board.

ok thanks

[xiangyu]

My boi Sahil wants some pics of some Machine ideas for division C.

Found this on youtube, my team used it as a basic concept and introduction to build our machine.
https://www.youtube.com/watch?v=qIEbVXtrMT0

[dayzdnconfused]

Thank you

[xiangyu]

Are there any videos to help me teach this to a student? this is my first time attempting simple machines...b division.
i am trying to figure out if two masses will be used. It mentions 3 masses in the rules, they are confusing. Any help at all would be appreciated. Don't worry, we probably won't win. I would at least like my student to be able to participate.

Oops! Didn't see your post from earlier, would've help sooner if I saw this. I'm not very active on the Machines thread, mostly on the building ones. Anyways, in terms of preparation, we just tried to do as much research as possible for each of the bullet points, remember, you can bring a binder to the event so find useful info! Wikipedia is a good starting point. The 3 masses are there just to test your machine's ability at different weights. You will be measuring and providing ratios of A/B and B/C I believe, so yes, two masses will be used at a time for most designs, but all three will be used in the competition. Also, you never know! Start with a good mindset and be ready to work hard and you could win! I really try to promote sharing at least to the basic level as science is more fun with collaboration. Anyways, let me know if you have further questions and I'll try to help!

Good luck!
Xiangyu

[waterboy]

Is anyone else confused about creating a graph to use on your device?

[xiangyu]

Is anyone else confused about creating a graph to use on your device?

I think it depends on your device. For example, I know some devices might have things set up so that at different ratios the levers might go to different angles (Not necessarily exact equilibrium, and mostly only applicable for C). This is what my first machine encounter, building a second one right now to try to get rid of that problem. If your device is built perfect spot on then yeah probably less likely you'll need to use the graph.

Xiangyu

[Giventhenumbers]

Question: I’m new at this event, and currently am working on figuring out how I would calculate mass ratios in the build portion of the event. I know it has to do with the law of levers, but what exactly would I do?
Im in división C, and am currently assembling the complex lever. I just need to figure out how I would calculate mass ratios. To fill in the blanks for distances, I’ll say 5 cm on one side of the class 2 lever, and 15 on the other.