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Re: Machines B/C

Posted: Thu Feb 20, 2020 7:31 pm
by CPScienceDude
as1092 wrote: Thu Feb 20, 2020 7:04 pm
Vortexx2 wrote: Tue Feb 11, 2020 7:50 am
Unome wrote: Mon Feb 03, 2020 1:20 pm

The scoring formula weights time more heavily this year iirc. I would not expect more than exceptional teams to be below 30 seconds in B and 40 seconds in C (with effectively perfect ratio scores of course).
I would have to disagree. I do it in around 40 seconds but thats also me going pretty slow. I could definitely see teams getting sub 30 seconds (div c) and still getting perfect ratio scores.
Is your machine built to have one mass fixed permanently? Because my design right now has a fixed place for the lighter mass, but I think it would be more efficient to have mass B fixed permanently, so I take on average 1:30 for time, with 29+ ratio score. Any help would be appreciated. Like how did you build your device bc 40 seconds seems close to impossible for me.
I can't vouch for vortexx, but I also get around 30ish sec and near-perfect ratio scores (~14.7/15 for each). I hang mass A on a fixed point, then move mass B to find the point where it's in equilibrium. Then take A off and put B on the fixed point and put C onto the lever and find equilibrium. See Here

Re: Machines B/C

Posted: Thu Feb 20, 2020 8:34 pm
by GurtYo
Hi! This might be a dumb question, but in rule 3a it says:
The device must be a class 1 lever with a single beam no longer than 80.0 cm.

I used a meter stick as my lever, and that is 100cm, so do I have to cut 20 cm off?

Re: Machines B/C

Posted: Thu Feb 20, 2020 9:28 pm
by MadCow2357
GurtYo wrote: Thu Feb 20, 2020 8:34 pm Hi! This might be a dumb question, but in rule 3a it says:
The device must be a class 1 lever with a single beam no longer than 80.0 cm.

I used a meter stick as my lever, and that is 100cm, so do I have to cut 20 cm off?
Yes

Re: Machines B/C

Posted: Fri Feb 21, 2020 12:15 pm
by as1092
CPScienceDude wrote: Thu Feb 20, 2020 7:31 pm
as1092 wrote: Thu Feb 20, 2020 7:04 pm
Vortexx2 wrote: Tue Feb 11, 2020 7:50 am

I would have to disagree. I do it in around 40 seconds but thats also me going pretty slow. I could definitely see teams getting sub 30 seconds (div c) and still getting perfect ratio scores.
Is your machine built to have one mass fixed permanently? Because my design right now has a fixed place for the lighter mass, but I think it would be more efficient to have mass B fixed permanently, so I take on average 1:30 for time, with 29+ ratio score. Any help would be appreciated. Like how did you build your device bc 40 seconds seems close to impossible for me.
I can't vouch for vortexx, but I also get around 30ish sec and near-perfect ratio scores (~14.7/15 for each). I hang mass A on a fixed point, then move mass B to find the point where it's in equilibrium. Then take A off and put B on the fixed point and put C onto the lever and find equilibrium. See Here
The video shows that one mass does not get replaced at all (i'm assuming it's mass B since you have to do A:B and B:C). How do you get 30 seconds while moving all 3 masses?

Re: Machines B/C

Posted: Fri Feb 21, 2020 12:26 pm
by CPScienceDude
as1092 wrote: Fri Feb 21, 2020 12:15 pm
CPScienceDude wrote: Thu Feb 20, 2020 7:31 pm
as1092 wrote: Thu Feb 20, 2020 7:04 pm

Is your machine built to have one mass fixed permanently? Because my design right now has a fixed place for the lighter mass, but I think it would be more efficient to have mass B fixed permanently, so I take on average 1:30 for time, with 29+ ratio score. Any help would be appreciated. Like how did you build your device bc 40 seconds seems close to impossible for me.
I can't vouch for vortexx, but I also get around 30ish sec and near-perfect ratio scores (~14.7/15 for each). I hang mass A on a fixed point, then move mass B to find the point where it's in equilibrium. Then take A off and put B on the fixed point and put C onto the lever and find equilibrium. See Here
The video shows that one mass does not get replaced at all (i'm assuming it's mass B since you have to do A:B and B:C). How do you get 30 seconds while moving all 3 masses?
Oops, bad example. But a similar idea. Ig I'm just fast? I have my partner calculate the ratios. So maybe that helps.

Re: Machines B/C

Posted: Mon Feb 24, 2020 2:40 pm
by Alex-RCHS
For those wanting an example graph, here's a link to one: https://www.sciencenc.com/wp-content/up ... -Graph.pdf

Note the disclaimers -- if your local ES has different interpretations of the rules, then I can't help you. :( The rules are unfortunately vague, especially 5.e.i.

Re: Machines B/C

Posted: Fri Feb 28, 2020 12:18 pm
by GurtYo
Hi! My partner and I aren't sure how to solve this kind of problem:
What effort force is required in order to keep the system in equilibrium. Assume that the system is ideal.

Re: Machines B/C

Posted: Fri Feb 28, 2020 12:27 pm
by CPScienceDude
GurtYo wrote: Fri Feb 28, 2020 12:18 pm Hi! My partner and I aren't sure how to solve this kind of problem:
What effort force is required in order to keep the system in equilibrium. Assume that the system is ideal.
You would have to find the amount of force the load exerts on the system, then divide that by the system's IMA.

Ex: There is a mass of 10.0 kg hanging off of one end of a class 1 lever. The side the mass is hanging on is 1.0m long from the fulcrum and the other arm is 4.0m long.

1. Multiply 10 x 9.8 to get the force it exerts. =98N
2. Find the IMA of the lever: 4/1 = 4.0
3. Divide the force by the IMA: 98N/4 = 24.5N (25 with SD's)

Re: Machines B/C

Posted: Mon Mar 23, 2020 10:45 am
by MoMoney$$$;)0)
Come on people we need to add to the best of 2020

Best of 2020

If you guys don't know how to add to the WIki, share me the photo privately, and I can add it on. :D

Re: Machines B/C

Posted: Mon Mar 23, 2020 11:13 am
by Creationist127
MoMoney$$$;)0) wrote: Mon Mar 23, 2020 10:45 am Come on people we need to add to the best of 2020

Best of 2020

If you guys don't know how to add to the WIki, share me the photo privately, and I can add it on. :D
I'd love to add, but my machine is locked up at school... plus I don't think it qualifies as best...