A question about floating

[jarod]

We know that the density of Al is greater than the density of water, yet why can an aluminum boat can float?

 

[ZapperZ]

http://hyperphysics.phy-astr.gsu.edu/hbase/pbuoy.html#arch

Zz.

 

[Integral]

We know that the density of Al is greater than the density of water, yet why can an aluminum boat can float?

If an Al boat puzzles you an Aircraft carrier must be simply amazing.

 

[russ_watters]

An aluminum boat floats, jarod, because it is made mostly of air! (by volume)

 

[rbj]

If an Al boat puzzles you an Aircraft carrier must be simply amazing.

when i was in school, i remember these civil engineering departments like to construct, as a demonstration, a concrete "canoe" and paddle that in a lake or river. not the most efficient watercraft, but it floats.

 

[jarod]

An aluminum boat floats, jarod, because it is made mostly of air! (by volume)

Is it what you meant was the overall density of the aluminum boat is less than the density of water?

 

[eaboujaoudeh]

yeah I've heard about making a concrete slab float, very difficult to do, we really had headaches when this problem was given to us...

 

[eaboujaoudeh]

yes actually the overall density of an object is related to center of gravity and composition of the boat, since the boat is not the Al. part only but also the air inside the total volume, this what makes it lighter than water