posted by Jack .
A 1.0 m cubed object floats in fresh water with 20% of it above the waterline. What does the object weigh out of the water?
See http://www.jiskha.com/display.cgi?id=1290346564 for explanation of Archimedes principle of floatation.
Basically an object floating in a fluid displaces a volume of fluid equal to its own weight.
So this 1 m³ object has 80% of it submerged. How much weighs the water it displaced? And its own weight equals?