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### Re: Scores B/C

Posted: January 20th, 2015, 9:56 pm
Ya at the current rate of things I would guess that the winning efficiency at nationals would probably be somewhere above 3000 (for division C) given the current rate of things.

### Re: Scores B/C

Posted: January 21st, 2015, 11:36 am
someusername wrote:Ya at the current rate of things I would guess that the winning efficiency at nationals would probably be somewhere above 3000 (for division C) given the current rate of things.
lol that circular statement.

### Re: Scores B/C

Posted: January 22nd, 2015, 6:13 am
Scioly99 wrote:
someusername wrote:Ive been getting scores in the 2600 to 2800 range. Any idea of how that might do at nationals assuming I cant successfully drop any more weight?

also how much does the woods density actually effect its strength?
I'd estimate a 2800 would get anywhere from 8th-4th place at nats, but I can't say for sure. I would almost guarantee that 1st place will be over 4000.
To score 4,000 points, the bridge would need to carry the full 15 KG load, and weigh less than 3.75 grams, measuring 450 mm long... it will never happen... I think the absolute highest for division C will be 3,500...

### Re: Scores B/C

Posted: January 22nd, 2015, 8:33 am
dholdgreve wrote:
Scioly99 wrote:
someusername wrote:Ive been getting scores in the 2600 to 2800 range. Any idea of how that might do at nationals assuming I cant successfully drop any more weight?

also how much does the woods density actually effect its strength?
I'd estimate a 2800 would get anywhere from 8th-4th place at nats, but I can't say for sure. I would almost guarantee that 1st place will be over 4000.
To score 4,000 points, the bridge would need to carry the full 15 KG load, and weigh less than 3.75 grams, measuring 450 mm long... it will never happen... I think the absolute highest for division C will be 3,500...
Never say never... and anyways I believe that Scioly99 was talking about Division B scores.

### Re: Scores B/C

Posted: January 22nd, 2015, 2:31 pm
Hi! I'm new here. i was wondering if anyone has an estimate for the efficiency of a bridge that is within the 1st - 3rd place range at both state and nationals for Division B.

### Re: Scores B/C

Posted: January 22nd, 2015, 3:37 pm
dragonzord0130 wrote:Hi! I'm new here. i was wondering if anyone has an estimate for the efficiency of a bridge that is within the 1st - 3rd place range at both state and nationals for Division B.
Well it would really depend on the state since some states are much more competitive than others but a general estimate for states can be around 3000-3500 for B division, and 2000-2500 C division. I would say you should expect a 4000 to get 1st in B division and 3000 for C division at nationals. Again, it really depends on the state that you are competing in.

### Re: Scores B/C

Posted: January 22nd, 2015, 3:39 pm
chinesesushi wrote:
dholdgreve wrote:
Scioly99 wrote: I'd estimate a 2800 would get anywhere from 8th-4th place at nats, but I can't say for sure. I would almost guarantee that 1st place will be over 4000.
To score 4,000 points, the bridge would need to carry the full 15 KG load, and weigh less than 3.75 grams, measuring 450 mm long... it will never happen... I think the absolute highest for division C will be 3,500...
Never say never... and anyways I believe that Scioly99 was talking about Division B scores.
What causes the difference between Div B and Div C scores anyway?

### Re: Scores B/C

Posted: January 22nd, 2015, 3:48 pm
Since the span of the bridges must be larger for C div, more material must be used to cover the increased span, which raises the mass of the structure. Also the larger span increases the forces in the bridge, which means larger pieces of wood are needed to hold the maximum load, again raising the mass of the structure. Since score is Mass held/mass of the structure, the increase of the mass of the structure leads to much lower scores.

### Re: Scores B/C

Posted: January 23rd, 2015, 6:10 am
DoctaDave wrote:Since the span of the bridges must be larger for C div, more material must be used to cover the increased span, which raises the mass of the structure. Also the larger span increases the forces in the bridge, which means larger pieces of wood are needed to hold the maximum load, again raising the mass of the structure. Since score is Mass held/mass of the structure, the increase of the mass of the structure leads to much lower scores.
... to add to the "Doctor," the span has increased without any increase in the load, I believe in theory that if the load limit were raised beyond the 15 KG to a proportionately equal load, the division C efficiency scores "wood" equal, or even surpass the Div B scores... With Division B designs, there is only so small you can get with the pieces, then there is just not enough lignen to hold the pieces together... This "wood" be substantially reduced with increased design parameters... The increase in scores "wood' come from at least 3 years of additional building experience, knowing what works and what doesn't.

### Re: Scores B/C

Posted: January 25th, 2015, 10:15 am
At the MIT invitationals tournament january 24, the efficiencies went as follows (In order of rank):

Solon High School 2390
Seven Lakes High School Team 1 2038
Seven Lakes High School Team 2 1580
Troy High School 1346
Bayard Rustin High School 1244
Stuyvesant High School 1181