Machines B/C

[Giventhenumbers]

Also, important question: will the weights given during competition be adjustable (I.e., on strings to hook on to the device) or would those have to be separately impounded?

[waterboy]

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

How would you use the graph for the B device, which is a class 1 lever

[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

How would you use the graph for the B device, which is a class 1 lever

I think the main idea is that the graphs show your process of device calibration. Your lever may not be equal at the start as one side is just slightly heavier than the other and the tables show the scientific process you took to add clay/sand off and tune the machine to make it better.

Xiangyu

[xiangyu]

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.

See the previous video link I posted, it should be a nice intro to the event. To summarize it real quick for you, basically you do "distance from fulcrum"/total "movable" lever length to get position ratio of one mass. Repeat this process for the other lever. Compare the two decimals, do A ratio/B ratio and you should get your answer. Of course, you do all these calculations after moving masses around and reaching equilibrium of levers.

I need to know more clearly what you mean by 5 cm and 15 cm, are they distances from the fulcurm? What's your lever length? etc.

Also disclaimer: my method might not be the best, and I would love to hear if others have an easier way.

Xiangyu

[Vortexx2]

The rules say we need 4 graphs/data tables. If I have 4 data tables of 10 data points each, is this sufficient?

[waterboy]

The rules say we need 4 graphs/data tables. If I have 4 data tables of 10 data points each, is this sufficient?

I think this would be sufficient as long as it meets the other requirements in 5.e.

[PandaShoelaces]

Part of the rules says this in section e of Event Parameters:

Event Supervisors will supply three masses labeled A, B, and C. A flexible loop, large enough to pass a standard golf ball through, must be tied to the top of each mass. The loops may be made from fishing line, zip ties, string, etc. The masses, including the fully stretched outflexible loop, must be able to fit inside a 15.0 cm x 15.0 cm x 20.0 cm box. Masses A, B, and C must be between 20.0 and 800.0 g.

These are simply directions to event supervisors, right? So, does this mean that the masses must be hung from the levers and not placed atop them?

[Vortexx2]

Part of the rules says this in section e of Event Parameters:

Event Supervisors will supply three masses labeled A, B, and C. A flexible loop, large enough to pass a standard golf ball through, must be tied to the top of each mass. The loops may be made from fishing line, zip ties, string, etc. The masses, including the fully stretched outflexible loop, must be able to fit inside a 15.0 cm x 15.0 cm x 20.0 cm box. Masses A, B, and C must be between 20.0 and 800.0 g.

These are simply directions to event supervisors, right? So, does this mean that the masses must be hung from the levers and not placed atop them?

Based off this section of the rules, I would say that the masses could be hung from the lever OR placed on top of them.

[InsertNameHere123]

Hey, so when the examiners weigh the masses before hand, does anyone know if they include the weight of the hook in their calculations for ratio? It's especially skewing in instances where the objects are really light, and I'm just worried that we're going to get skewed if the hook for the practical isn't included. Thanks in advance!

[waterboy]

Hey, so when the examiners weigh the masses before hand, does anyone know if they include the weight of the hook in their calculations for ratio? It's especially skewing in instances where the objects are really light, and I'm just worried that we're going to get skewed if the hook for the practical isn't included. Thanks in advance!

Because you are trying to find the ratio of two masses and not the actual masses of the two objects, I don't think the weight of the hook matters as long as they are the same for each of the weights.