CrawfishDiver
Contributor
How much water does the avg person displace? is thier a way to calculate with just known weight?
water displacement
- Thread starter CrawfishDiver
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
You wouldn't be able to calculate displacment with mass alone, as displacement would be determined by the volume of the body. However, you could do the great Archemedies demonstration, filling up your bathtub to the brim, going in and measuring the volume that comes over the side, and then run down your street yelling " EURIKA! EURIKA!" completly naked. Might get your arrested though.
OP
CrawfishDiver
Contributor
still a little cold for that !!
fisherdvm
Contributor
- Messages
- 3,577
- Reaction score
- 52
- # of dives
- 200 - 499
Divide your weight in lbs to 2.2 to convert to KG. Each KG is equal to 1 liter of water, or 1000cc. An average man weights 70 kg, so he will displace about 70 liters of water.
A lean person will be slightly negative buoyant. Most will be slightly positive with a full breath.
The above conversion will underestimate water displaced by a woman or an obese man, due to their increased fat percentage... But will come pretty darn close.
A lean person will be slightly negative buoyant. Most will be slightly positive with a full breath.
The above conversion will underestimate water displaced by a woman or an obese man, due to their increased fat percentage... But will come pretty darn close.
Guba
Contributor
I'll take a shot at it...
This is assuming you're diving and you have absolute neutral buoyancy. That means that you and your equipment are, for all practical purposes, the same density as the water around you (your average density, that is). Sea water has a weight of 64.08 pounds per cubic foot. So, for a 185 lb person...
185 lbs X 1cubic foot/64.08 lbs = 2.89 cubic feet of volume
I know that doesn't fully answer your question, because you probably want to know the volume of the person alone. That's a bit more complex, because then we need to know that person's density. That varies quite a bit with condition, BMI, etc...
Good luck with that one. Perhaps the best bet would be to try sciguyman's "dunking technique" (but be sure you completely submerge to take the reading. Can't forget the part of the body that floats above the surface!)
This is assuming you're diving and you have absolute neutral buoyancy. That means that you and your equipment are, for all practical purposes, the same density as the water around you (your average density, that is). Sea water has a weight of 64.08 pounds per cubic foot. So, for a 185 lb person...
185 lbs X 1cubic foot/64.08 lbs = 2.89 cubic feet of volume
I know that doesn't fully answer your question, because you probably want to know the volume of the person alone. That's a bit more complex, because then we need to know that person's density. That varies quite a bit with condition, BMI, etc...
Good luck with that one. Perhaps the best bet would be to try sciguyman's "dunking technique" (but be sure you completely submerge to take the reading. Can't forget the part of the body that floats above the surface!)
- Messages
- 22,171
- Reaction score
- 2,798
- # of dives
- 5000 - ∞
Get in the pool. Weight yourself till neutral, the rest should be obvious, if not send $50 via PayPal for my Archemedian Specialty course. Instead of a patch you get a bust.
CrawfishDiver:
No .
Don Burke
Contributor
With just known weight, no.CrawfishDiver:
If you get in a pool and weight yourself until neutral you have a chance.
Total weight of a object neutral in fresh water divided by 62.4 will give you displacement in cubic feet.
Similar threads
