# Formulas

Discussion in 'Stability' started by U.S.S. Guppy, Feb 14, 2007.

1. Joined: Feb 2007
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### U.S.S. GuppyKainz Racing #K2

I need the formulas for draft, and buoyancy. Any info is greatly appriciated.

2. Joined: Aug 2004
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### jehardimanSenior Member

The double intergral over dx and dy evaluated against any given Z draft is buoyancy. What more do you need?

3. Joined: Feb 2007
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Location: Goodridge, Minnesota

### U.S.S. GuppyKainz Racing #K2

the prob is that im 16 and i dont no what the heck double intergral is what dx and dx are and what a z draft is... haha

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### jehardimanSenior Member

I knew what they were when I was 16... Learn to spell and learn calculus. Mathematics is the language of science.

Why don't you go troll Youtube.

5. Joined: Feb 2007
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### U.S.S. GuppyKainz Racing #K2

y dont u just help me and not make a big deal out of it

6. Joined: Apr 2006
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### IkeSenior Member

When you are at school go to the math teacher and ask him about simpsons rule, also called simpsons formula. (if they teach algebra, geometry or trig they should know what simpsons rule is.) or you can just google it. That is what you need to start with. Any one who can add, subtract, multiply and divided can use simpsons rule. Simpsons will give you the volume of the boat that is submerged. Multiply that volume by 64 (62.4 for fresh water) and that is the displacement of the boat.

The draft is simply how far the boat sticks down in the water. If you know the displacement you can work it backwards to find the draft. displacement divided by 64 is the volume of the boat underwater. From the volume you can figure out how much is underwater.

Bouyancy is the displacement less the weight of what is displacing the water. SO if you know displacement then you know buoyancy. I'll explain it this way. A cubic foot of air will displace one cubic foot of water. That is 64 lbs of salt water, 62.4 pounds in fresh water. So you also have 64 pounds of buoyancy. However, if the cubic foot has weight, say a cubic foot of foam that weighs 2 pounds, Then intead of 64 pounds of bouyancy you have 62 ilbs of buoyancy (64-2=62)

Have I confused you yet? Here's a link to buoyancy on Wikipedia. Read what it says about Archimedes Principle. Yeah this stuff is not that hard. Even the Greeks had it figured out.

And you don't need to know Calculus or Differential Equations

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### WillallisonSenior Member

You having a bad hair day JH?......

8. ### Chris OstlindPrevious Member

Yes, John, and I suppose you could swim the 100 meter free in under 55 sec., you had no zits, had the bitchinest hotrod and you were the most popular guy on campus with the ladies.

Thanks for being kind, Ike.

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### ABoatGuyMember

JH

Troll YouTube for "manners". . . You may be great at spelling and a calculus genius but you may need work on "getting along with others".

10. Joined: Aug 2004
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### jehardimanSenior Member

Yeah; and drunk and sad, and angry at myself for being drunk and sad. And un-happy with people who think quick is spelled "Qwik" and you = "u". Texting shortcuts their place, but when asking for education is not it.

Nah...best I could do was about 1:05. Never learned to butterfly (popular at the time, now replaced by the crawl) but my mother was a WSI and I could almost keep up with a trudgon.
Zits got better after I started using tetracycline but the sunburns caused a lot of scaring, especally on the hands.
I did have the fastest car though...a '66 Plymouth Satellite. An original hemi car (RP23H), the hemi was removed by the original owner for a short tracker and we bought the body and running gear with a D500 361 in it when he need to build a new stocker. For some reason they left the 18-spline A833 transmission and the 3.54 Dyna 60 with snubber on 7 leaf springs in it. Anyway, we put a ported, CC'd, and decked forged crank 440 out of a totaled 67 GTX with a Racer Brown cam, pro-stock pressure plate, Edelbrock STR-14, and Holly Dominator with .105 primaries. Would turn 11s~120mph with street tires if you could keep them hooked up.
Never was able to get a date in high school. Both the girls I asked to the prom turned me down, so I didn't go.

Can't connect to YouTube...dialup times out you know. I thought YouTube was for people posting "look at this geek/look at me" videos of uncivil behavior, not an interactive forum concept. Guess I'll have to get with the program.

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### duluthboatsSenior Dreamer

“I need the formulas for draft, and buoyancy. Any info is greatly appriciated.”

The search button is the first place to go on this site. Some topics have been covered many times. If you don’t find the answer at least it may help you in phrasing your question. Take some time to tell us why you are asking. Many of the most knowledgeable people on this site will gladly help, if you show a little deference. Using PC shorthand is not APPRECIATED.

http://www.tedbrewer.com/yachtdesign.html

Gary

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### gonzoSenior Member

I think many of us old guys don't appreciate shorthand because we don't get it. It's a whole new way of communicating faster.

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