Machines B/C

[GurtYo]

Are you allowed to bring a ruler to use when calculating your ratios? According to rule 2b, you can bring "tools". Does this include a ruler?

[CPScienceDude]

Are you allowed to bring a ruler to use when calculating your ratios? According to rule 2b, you can bring "tools". Does this include a ruler?

I wouldn't see why a ruler would not be included. Though I made the arms of my lever out of a cut-up yardstick, so I get to bypass having a ruler

[shrewdPanther46]

How accurate are winning devices expected to be at this time in the year?

[Unome]

How accurate are winning devices expected to be at this time in the year?

Accurate enough that the differences in accuracy at the top is negligible.

[bergerbaby]

Question: For division B, incline planes, do you think for Div B they will ask the students to find Incline Planes with Friction, it seems that it involves some trigonometry and not sure we have had that yet?

[Creationist127]

Question: For division B, incline planes, do you think for Div B they will ask the students to find Incline Planes with Friction, it seems that it involves some trigonometry and not sure we have had that yet?

Probably not--the only mention of friction in the rules is under Division C Only.

[Epicbanna4]

Hi all who see this; I have a rule question. Rule 3e. states, "Participants must not bring masses or include them in devices except when fixed in place prior to impound to obtain static equilibrium" I realize that this means counterweights must be fixed in place; however, what is the official definition of fixed in place? Does that mean IMPOSSIBLE to remove, or HARD to remove, or what? Because my counterweight isn't permanently there-it can be moved but takes a nominal-ish amount of force.

[knightmoves]

Hi all who see this; I have a rule question. Rule 3e. states, "Participants must not bring masses or include them in devices except when fixed in place prior to impound to obtain static equilibrium" I realize that this means counterweights must be fixed in place; however, what is the official definition of fixed in place? Does that mean IMPOSSIBLE to remove, or HARD to remove, or what? Because my counterweight isn't permanently there-it can be moved but takes a nominal-ish amount of force.

"Fixed in place" would mean to me that, by design, it does not move for the duration of the day of competition. You must not in any sense attempt to use it as adjustable. Somehting that is screwed together is "fixed in place" even though you can unscrew it. Something that is held in place only with a finger-tight screw clamp that you could easily adjust during the event is not fixed in place.

[shrewdPanther46]

Hi all who see this; I have a rule question. Rule 3e. states, "Participants must not bring masses or include them in devices except when fixed in place prior to impound to obtain static equilibrium" I realize that this means counterweights must be fixed in place; however, what is the official definition of fixed in place? Does that mean IMPOSSIBLE to remove, or HARD to remove, or what? Because my counterweight isn't permanently there-it can be moved but takes a nominal-ish amount of force.

"Fixed in place" would mean to me that, by design, it does not move for the duration of the day of competition. You must not in any sense attempt to use it as adjustable. Somehting that is screwed together is "fixed in place" even though you can unscrew it. Something that is held in place only with a finger-tight screw clamp that you could easily adjust during the event is not fixed in place.

for more sensitive devices wouldnt this be a problem? I would imagine some people would have devices that are sensitive and need to adjust it during the setup period. That rule doesnt make sense to me.

[vyang328]

I have a question regarding what a class 2 lever should look like of Div C. My partner and I didn't really think things through before making building our device and both of our beams have the fulcrum in the middle of the beam. I acknowledge that this wasn't a smart design but oh well, still have regionals to improve it.

One of them is a class one with the weights being hanged on the left and a string connected to the beam on the right.
For the other beam, the fulcrum is in the middle of the beam but we plan on putting the weight between where the beams are connected on the end and the fulcrum (aka resistance between effort and fulcrum).

Does this still count as a class 2 lever? Most pictures of class 2/3s have the fulcrums all the way at the end of beam so I'm worried we might get put into tier 2 immediately at impound.