Here are the steps Jake can take to find the density of the book using the tools he has: 1. Use the balance to measure the mass of the book. Let's say it's 1,000 grams. 2. Use the ruler to measure the dimensions of the book - its length, width, and height. 3. Calculate the volume of the book by multiplying its length by its width by its height. For example, if the book is 20 cm long, 10 cm wide, and 2 cm thick, its volume would be 20 cm x 10 cm x 2 cm = 400 cm3. 4. Use the density formula: Density = Mass / Volume 5. Plug in the values:

1. DENSITYDENSITY
Q) Which weighs more:-
A kilogram of feathers or a kilogram of iron?

2. What is Density?What is Density?
Density is the Mass per unit
Volume
Wood Water Iron
1 cm3
1 cm3 1 cm3
If you take the same volume of different substances,
then they will weigh different amounts.
0.50 g 1.00 g 8.00 g
Q) Which has the greatest mass and therefore the most dense?
IRON

3. Density is defined as mass per unit volume. It
is a measure of how tightly packed and how
heavy the molecules are in an object. Density
is the amount of matter within a certain volume.
Its unit is g/cm3
or kg/m3
Density

4. Density = Mass
Volume
g or kg
cm3
or kg3
gcm-3
or kgm-3
ρ = m
V
Example:
Q) Liquid water has a density of
1000kgm-3
, while ice has density of
920kgm-3
.
Calculate the volume occupied by
0.25kg of each.
Density Equation:
m
Vρ
V = m = 0.25 = 0.000250m3
ρ 1000
V = m = 0.25 = 0.000272m3
ρ 920

5. Change Mass AND Keep Volume SameChange Mass AND Keep Volume Same
Increase the massIncrease the mass  increases densityincreases density
Decrease the massDecrease the mass  decreasesdecreases
densitydensity
Which container has more density?Which container has more density?
AA BB
Ways to Affect Density

6. Change Volume AND Keep Mass SameChange Volume AND Keep Mass Same
Increase the volumeIncrease the volume  decreases densitydecreases density
Decrease the volumeDecrease the volume  increases densityincreases density
Which container has more density?Which container has more density?
 A BA B
Ways to Affect Density

7. DENSITY OF A REGULAR SOLIDDENSITY OF A REGULAR SOLID
 Find the Mass ofFind the Mass of
the solid on athe solid on a
balance.balance.
 Measure theMeasure the
three lengths andthree lengths and
calculate thecalculate the
Volume.Volume.
(ie V = l x w x h )(ie V = l x w x h )
 Calculate theCalculate the
Density.Density.4.0 cm
2.0 cm
3.0 cm
ρ = m = 240 =10.0 g/cm3
V 24
m = 240 g

8. DENSITYDENSITY g/cmg/cm33
AluminiumAluminium 2.702.70
BrassBrass 8.508.50
IronIron 7.867.86
WoodWood 0.500.50
SlateSlate 2.802.80
GlassGlass 2.502.50
LeadLead 11.311.3
MarbleMarble 2.702.70
WaxWax 0.890.89

9. DENSITY OF AN IRREGULARDENSITY OF AN IRREGULAR
SOLIDSOLID
 Find the Mass of the solidFind the Mass of the solid
on a balance.on a balance.
Fill the Measuring CylinderFill the Measuring Cylinder
with Water to a knownwith Water to a known
Volume.Volume.
 Add the Object.Add the Object.
 Work out the Volume ofWork out the Volume of
Water that is displaced.Water that is displaced.
 Calculate the Density.Calculate the Density.
50 cm3
80 cm3
m = 360 g
ρ = m = 360 =12.0 g/cm3
V 30

10. DENSITY OF A FLOATINGDENSITY OF A FLOATING
OBJECTOBJECT
 Find the Mass of the object onFind the Mass of the object on
a balance.a balance.
Add some amount of Water toAdd some amount of Water to
a Measuring Cylindera Measuring Cylinder
 Add only the steel ball firstAdd only the steel ball first
 Find the Volume of WaterFind the Volume of Water
Now add the steel ball alongNow add the steel ball along
with the objectwith the object
Find the volume of waterFind the volume of water
displaceddisplaced
Calculate the Density.Calculate the Density.
50 cm3
80 cm3
m = 36 g
ρ = m = 36 =3.6 g/cm3
V 10
90 cm3

11. DENSITY OF A LIQUIDDENSITY OF A LIQUID
 Find the Mass of an emptyFind the Mass of an empty
Measuring Cylinder.Measuring Cylinder.
 Add a certain Volume ofAdd a certain Volume of
Liquid.Liquid.
 Find the Mass of theFind the Mass of the
Measuring Cylinder and LiquidMeasuring Cylinder and Liquid
 Calculate the Mass of Liquid.Calculate the Mass of Liquid.
 How?How?
 Calculate Density of Liquid.Calculate Density of Liquid.
Mass of Liquid = Mass of Measuring Cylinder and Liquid – Mass
of
empty Measuring Cylinder
25.0 g
20.0 cm3
45.0 g
45 – 25 = 20 g
ρ = m = 20 =1.00 g/cm3
V 20

12. If you have 2 or more
liquids,
the MORE dense
liquid will be on
bottom
The LESS dense
liquid will be on top

13. Let’s try some density problemsLet’s try some density problems
togethertogether
1 Frank has a paper clip. It has a mass of 9g and1 Frank has a paper clip. It has a mass of 9g and
a volume of 3cma volume of 3cm33
. What is its density?. What is its density?
2. Frank also has a pen. It has a mass of 3g, but2. Frank also has a pen. It has a mass of 3g, but
he doesnot know the volume. Explain how hehe doesnot know the volume. Explain how he
can find the density by giving appropriatecan find the density by giving appropriate
values as examples.values as examples.

14. Super Scientist
Question of the Day
• Jake has a book, a ruler, and a
balance.
•
• How can Jake find the density of
the book with the tools he has?