MadSci Network: Physics

Re: Since Archimedes Principle states a floating object displaces its weight in

Date: Mon Mar 19 09:50:44 2001
Posted By: Erika Gibb, Grad student, Physics & Astronomy/Origins of Life, RPI
Area of science: Physics
ID: 984172042.Ph

Hi James,

Whether or not something floats depends not just on its mass, but its
density (which is its mass/volume).  If it will displace less mass than an
equivalent volume of water, then that object will float.  Ice floats on
water because it has a lower density.  Marbles will sink because they are
denser than water.  It is possible to have a very dense material float if
there is enough empty volume to make the average density less than that of
water, such as a hollow marble.  You could also , for example, make it bowl
shaped or make it with a large bottom surface area and shallow sides (much
like a cookie sheet).  In all these cases you have the dense material
filled with air which lowers the average density.

Hence, it is possible to float something that weighs more than the water
you are floating it in.  In principle you could float a 1000000 pound boat
in 100 pounds of water by making the boat out of a material that has a very
low density or by making it with a very large, thin bottom.  However, it is
not really very practical as it would be difficult to find a 1000000 pound
boat that will fit in the space taken up by 100 pounds of water.


Current Queue | Current Queue for Physics | Physics archives

Try the links in the MadSci Library for more information on Physics.

MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci

MadSci Network,
© 1995-2001. All rights reserved.