Regarding the buoyancy of 1-1/2" Schedule 40 PVC tubes used for tripod
leg protection in water.
Weight per foot = 0.51 lbs.
Inside diameter = 1.61"
Weight of water per cubic inch = .0361 lbs.
Internal displacement per foot =
12 x pi x (1.61/2)*2 = 24.42 cubic inches
buoyancy per foot =
(24.42 cubic inches x 0.0361 lbs) - 0.51 lbs =
Three legs at three feet each gives a lifting force of
3 x 3 x 0.37 = 3.33 lbs
or thereabouts. Presumably the actual is much less since not all three
feet of the pipes length will likely be under water. Also, I have not
corrected for the difference in weight between fresh and seawater :-)
Anyhow, the tripod is not likely to go floating away.
Woburn, Massachusetts, USA
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >