### By Archimedes` principle

```Prepared By : NUR AZWANI BINTI ZAMRI (A131388)
DEFINITION OF
ARCHIMEDES PRINCIPLE
An object is immersed in a fluid is buoyed up by a
force equal to the weight of the fluid displaced
by the object.
FORMULA OF
ARCHIMEDES PRINCIPLE
FB = wA –wF
Where ;
FB is again the buoyant force on the object,
wA is the normal weight of the object measured in
air (wA = m g), and
wF is the weight taken while the object is immersed
in a fluid of density rF.
SIMPLE EXPERIMENT OF
PRINCIPLE ARCHIMEDES
CALCULATION
From the equation : FB = wA –wF
According to experiment ;
wA = 640g , Wf = 410g (by referring to water displacement,230g )
FB = wA –wF
= 640g – 410g
= 230g
STATE OF BOUYANCY
Buoyancy is always an upward force created by a fluid.
Positive
• If an object floats, it means the object displaces an amount of
water that weighs more than the object does. In other words, the
object is less dense than the water.
Negative
• If an object displaces an amount of water that weighs less than the
object does, it sinks. Because the object is denser than the water,
the water does not provide sufficient buoyancy to make it hover or
float.
Neutral
• If an object is neutral, it hovers. This means the object displaces an
amount of water that weighs the same as it does.
APPLICATION OF
PRINCIPLE ARCHIMEDES
1) SUBMARINE
A submarine has a large ballast tank, which is used
to control its position and depth from the surface of
the sea.
A submarine submerges by letting water into the
ballast tank so that its weight becomes greater than
the buoyant force (and vice versa). It floats by reducing
water in the ballast tank.-thus its weight is less than
the buoyant force.
2.HOT AIR BALLON
- The atmosphere is filled with air that exerts buoyant
force on any object.
- A hot air balloon rises and floats due to the buoyant
force (when the surrounding air is greater than its
weight). It descends when the balloon weight is more
than the buoyant force. It becomes stationary when the
weight = buoyant force.
- The weight of the Hot-air balloon can be controlled
by varying the quantity of hot air in the balloon.
3. SHIP
- A ship floats on the surface of the sea because
the volume of water displaced by the ship is
enough to have a weight equal to the weight of
the ship.
- A ship is constructed in a way so that the shape
is hollow, to make the overall density of the ship
lesser than the sea water. Therefore, the buoyant
force acting on the ship is large enough to support
its weight.
CONCLUSION
By Archimedes’ principle,
Upthrust on body = Weight of fluid displaced
Therefore,
Weight of floating body = Weight of fluid displaced
This result, sometimes called the “principle of floatation”,
is a special case of Archimedes’ principle and can be
stated: A floating body displaces its own weight of fluid.
REFERENCES
REFERENCES
•• John
JohnW.Jeweett,Jr,
W.Jeweett,Jr,2010,
2010,Physics
Physicsfor
forscientist
scientist
and
andEngineers
Engineerswith
withmodern
modernPhysics,
Physics,8th
8th
Edition
Edition
•• http://wikipedia.org/wiki/Archimedes_index
http://wikipedia.org/wiki/Archimedes_index
```