buoyancy notes

1. Buoyancy
 Buoyant force isthe force on an object
exertedbythe surroundingfluid.
 Whenan objectpusheswater,the waterpushes
back withas muchforce as itcan.
 If the watercan pushback as hard, the object
floats(boat). If not,it sinks (steel).
Archimedes’ Principle
 Statesthat the buoyantforce isequal to the
weightof the fluidthe objectdisplaces.
 1 cm3
of steel weighsmore thanthe 1 cm3
of
waterit displaces,soitsinks. 1 cm3
of ice weighs
lessandso it is pushedup.
How to measure the buoyant force
 Weightof objectinair - weightof objectinwater
= upwardbuoyantforce.
 The buoyantforce is equal tothe weightof the
displacedwater
c

2. Buoyancy
 Buoyant force isthe force on an object
exertedbythe surroundingfluid.
 Whenan objectpusheswater,the water
pushesbackwithas much force as it can.
 If the watercan pushback as hard, the object
floats(boat). If not,it sinks(steel).
Archimedes’ Principle
 Statesthat the buoyantforce isequal to the
weightof the fluidthe object displaces.
 1 cm3
of steel weighsmore thanthe 1 cm3
of
waterit displaces,soitsinks. 1 cm3
of ice
weighslessandsoitis pushedup.
How to measure the buoyant force
 Weightof objectinair - weightof objectin
water= upwardbuoyant force.
 The buoyantforce is equal tothe weightof the
displacedwater
As the submarine dives, the ballast tanks are
flooded with water and the air in the ballast tanks
is vented from the submarine until its overall
density is greater than the surrounding water and
the submarinebegins to sink (negative buoyancy).