1. No category

Why Did the Titanic Sink?
How did this happen?
Need to know:




Buoyancy
Archimedes’ Principle
Why do some things sink, while
others float?
What Happened to the Titanic?
What is Buoyancy?


The Greek scientist Archimedes (287
B.C. – 212 B.C.) discovered that
objects floating in a liquid are
supported by an upward force.
Simply put, buoyancy is the ability of
an object to float.
Archimedes’ Principle! Eureka!




Archimedes discovered that the buoyant
upward force on a floating object is equal
to the weight of the liquid that the object
displaces.
For example, if an inflatable boat is placed
in water and 100 lbs of water is displaced,
then the buoyant upward force MUST be
100 lbs of force.
Word equation: Buoyant force=weight of
liquid displaced=loss of weight in liquid
Also, BF=weight of object in air-weight in
liquid
WHEW! That was a lot of
information! Stick with me…..
So how can a ship float?




A ship can float because it’s constructed
with many air-filled chambers.
Air, as we all know, weighs less than water
So, the combined weight of the air and
steel of the ship weighs less than the
weight of the water displaced by the ship
So, the ship floats!
So???



So this principle determines what
sinks and what floats
If an object weighs more than the
water it displaces, it will sink.
Quarter vs. aluminum foil! They are
both metal, so they should sink,
right? MAKE A PREDICTION!!
Wow!


The quarter sank because weighed
more than the water it displaced! It
is a solid coin
The aluminum foil floated because of
the air within it. Air weighs less than
water!
What Happened to the Titanic? It
was Archimedes’ Principle!





The “unsinkable ship” was en route to NYC
in 1912
On April 14, it struck an iceberg
The collision ripped a huge hole in the hull
of the ship, causing the air filled pockets
to fill with water
This added weight became greater than
the buoyant force supporting the ship, so
it sank. Rapidly.
About 1500 lives were lost
Let’s Sum it Up!



An object sinks when the weight of the
object is greater than the buoyant force
that supports it (quarter)
An object floats when its weight is less
than the buoyant force that supports it
(Aluminum foil)
Archimedes’ Principle is that the
BF=weight of object in air-weight of object
in water or the BF=the weight of liquid
displaced=loss of weight in liquid