Chapter 3, Section 3
Pg. 82
Floating and Sinking
Archimedes’ Story
How can I figure out if
it’s real?
What’s this? the
water rises when I
get in!!! Hmmm…
Same Weight
and Volume?
The crown has
silver in it and
gold is pure!
Archimedes’ Story
1.
2.
3.
When you place an object in
water, the rise in water is due to
______ ___________.
Density depends on 2 things,
__________ and ___________.
Density is the reason objects
_________ or _________ in fluids.
Volume
Density
1.
2.
To figure out the Density of an
object, divide the object’s ________
by it’s __________.
___________ is how much space
something takes up.
The Density Triangle



Density = mass per unit volume
Per means divide!
Unit means a single amount.
M
D
V
Density
 Same
Volume  Different Volume
 Different Mass  Same Mass
Density
Does greater volume or less mass
make Diet Coke float? How do you
know?
Density
1.
2.
3.
If an object is More dense than the
fluid it is in, it will _________.
If an object is Less dense than the
fluid it is in, it will _________.
If a block of wood has a mass of 200
grams and has a volume of 4 liters,
what is its density?
Density
Less Dense
Dive
Dive!!
More Dense
Buoyancy (Boy – unsee)
1.
2.
Water exerts a force
called the
___________ force on
submerged objects.
What does submerge
mean?
Buoyancy
The buoyant force on a object is equal to
the weight of the fluid displaced by the
object.
If they have the same mass why does one sink
and the other float?
Buoyancy
1.
Buoyant force acts in the ________
direction, against the force of
__________, so it makes an object
feel ________.
Density Review
1.
2.
3.
Why does a balloon filled with helium
rise in air?
Why does an ordinary balloon fall in
air?
How do submarines dive into and
rise out of the water?