Use Archimedes' law of buoyancy.

Question

- to calculate what fraction of the volume of an iceberg floating in the ocean is above the water level.
-how many 20kg penguins can be supported by a 1000 cubic meter iceberg that is on the verge of being completely submerged?

Answer 1

physics-buoyancy - bobpursley, Monday, May 9, 2011 at 6:12am

you need the density of ice, and the density of sea water. abbreviate these as di, and ds

weight of iceberg: di*VolumeIce*g
weight of displaced seawater: ds*VolumeIce*k*g where k is a fraction

Archemedes says these two forces are the same.

di*volumice=ds*volumeice*k

solve for k.

Now, knowing k, you can solve the penguin question.

volumeice*di*g+ mg =volumeice*ds*k*g

so when k equals 1, it is submerged, so

m=volumeice(ds-di)

numberpenguins*20=m=above

solve for number penguins.