Density

Warming UP

Multiple Choice

What is the correct SI unit for mass?

• Kilograms

• newtons

• pounds

• grams

Multiple Choice

The SI unit for temperature is __?__.

• degree fahrenheit  (° F)

• degree celsius  (° C)

• kelvin  (K)

• degree centigrade  (°C)

Multiple Choice

What SI unit is used to measure length?

• meters

• liters

• centimeters

• kilograms

Multiple Choice

The SI unit for time is the __?__.

• hours (h)

• liter (L)

• gram (g)

• second (s)

Multiple Choice

How many unit cube are there in each solid?

• 5 unit cubes

• 6 unit cubes

• 7 unit cubes

• 8 unit cubes

How to know the pure gold in jewelry?

PHYSICS – Density

LEARNING

OBJECTIVES

1.4 Density
Core
• Recall and use the equation ρ =
m/V
• Describe an experiment to
determine the density of a liquid
and of a regularly shaped solid and
make the necessary calculation
• Describe the determination of
the density of an irregularly
shaped solid by the method of
displacement
• Predict whether an object will
float based on density data

SI units

(Le Systeme International d’Unites)

SI units

(Le Systeme International d’Unites)

Volume → cubic metre (m3)

1m

1m

1m

SI units

(Le Systeme International d’Unites)

Volume → cubic metre (m3)

1m

1m

1m

1 cubic metre = 1m x 1m x 1m

SI units

(Le Systeme International d’Unites)

Volume → cubic metre (m3)

1m

1m

1m

1 cubic metre = 1m x 1m x 1m

1 cubic metre (1m3)

= 1000 litres (l)

Multiple Choice

Calculate the Volume

• 410 $$cm^3$$

• 420 $$cm^3$$

• 402 $$cm^3$$

• 401 $$cm^3$$

1 litre bottle = 1l

Same as 1 cubic
decimetre (dm3)

1 litre bottle = 1l

Same as 1 cubic
decimetre (dm3)

1 litre = 1000 cubic centimetres (cm3)

= 1000 millilitres (ml)

1 litre bottle = 1l

Same as 1 cubic
decimetre (dm3)

1 litre = 1000 cubic centimetres (cm3)

= 1000 millilitres (ml)

1 cubic centimetre (cm3) = 1 millilitre (ml)

1 cm

1 cm

1 cm

1 litre bottle = 1l

Same as 1 cubic
decimetre (dm3)

1 litre = 1000 cubic centimetres (cm3)

= 1000 millilitres (ml)

1 cubic centimetre (cm3) = 1 millilitre (ml)

1 cm

1 cm

1 cm

Aluminium

Lead

For any given volume (eg. 1cm3) lead is
heavier than aluminium. It has a higher

DENSITY

Poll

See the video, in your opinion if we put Balsa wood and metal pin, what happen to them?

• Balsa wood will sink

• Metal pin will sink

• Metal pin will float

• Both of them will sink

Poll

See the video! In your opinion, why its happen?

• Because they have same density

• Because they have different density

Video Response

What is density?

Open Video Recorder

DENSITY = Mass

Volume

DENSITY = Mass

Volume

Water has a
density of

1 g/cm3

1000 cm3of water (1 litre) therefore

has a mass of 1000g (1 kilogram)

DENSITY = Mass

Volume

Water has a
density of

1 g/cm3

1000 cm3of water (1 litre) therefore

has a mass of 1000g (1 kilogram)

Substance

Density (g/cm3)

Wood

0.75

Ice

0.92

Water

1.00

Aluminium

2.70

Copper

8.90

Lead

11.4

DENSITY = Mass

Volume

Water has a
density of

1 g/cm3

1000 cm3of water (1 litre) therefore

has a mass of 1000g (1 kilogram)

Substance

Density (g/cm3)

Wood

0.75

Ice

0.92

Water

1.00

Aluminium

2.70

Copper

8.90

Lead

11.4

THINK!

A solid object with a density lower

than that of water will float.

So why should a battleship made of

aluminium not sink?

Calculating density

In the density equation,
density is shown by the
Greek letter ‘rho’ =

DENSITY = Mass

Volume

= m

V

Calculating density

In the density equation,
density is shown by the
Greek letter ‘rho’ =

DENSITY = Mass

Volume

= m

V

m

V

V = m

m = V x

Calculating density

m

V

Eg. What is the density of a block of
steel if it has a mass of 9,360g and a
volume of 1,200cm3?

Calculating density

m

V

Eg. What is the density of a block of
steel if it has a mass of 9,360g and a
volume of 1,200cm3?

= 9 360

1 200

= 7.8 g/cm3

Multiple Choice

What is the formula for density?

• density = mass x volume

• density = mass / volume

• density = mass + volume

• density = mass - volume

Multiple Choice

What two types of measurements make up DENSITY? 

• Mass and Volume

• Temperature and Mass

• Grams and Centimeters

• Volume and Weight

Multiple Choice

Frank has a paper clip. It has a mass of 9g and a volume of 3cm³. What is its density?

• 3 g/cm³

• 1/3 g/cm³

• 27 g/cm³

• 39 g/cm³

Multiple Choice

What units are used to measure mass?

• g

• cm³

• g/cm³

• cm³/g

Calculating density

m

V

Eg. What is the density of a block of
steel if it has a mass of 9,360g and a
volume of 1,200cm3?

= 9 360

1 200

= 7.8 g/cm3

Eg. What is the mass of a block of gold if
it has a density of 19.3 g/cm3and a
volume of 540 cm3?

m = 540 x 19.3 = 10,422g

Volume and Density

Volume of a liquid

Measuring cylinder

Read off the level on the scale to
get the volume of liquid

Volume and Density

Volume of a
regular solid

Length

Height

Width

Volume of rectangular block = length x width x height

Volume and Density

Volume of a
regular solid

Length

Height

Width

Volume of rectangular block = length x width x height

Height

Radius

Volume of a cylinder= π x radius2x height

Volume and Density

Volume of an
irregular solid

Read off the level on the scale
before adding the irregular solid,
and again after the solid has been
put into the measuring cylinder.

Volume of irregular solid =

Volume after – volume before

Eg. 235 – 155 = 80cm3

Volume and Density

Volume of an
irregular solid

Using a Eureka (displacement) can

Fill the Eureka can until it stops
over-flowing.

Gently lower the irregular solid
into the can and measure how
much displaced liquid is collected
in the measuring cylinder.

Volume and Density

Volume of an
irregular solid

Using a Eureka (displacement) can

Mass of irregular solid = 350g

Volume of irregular solid = 80cm3

Density = mass / volume

Density = 350 / 80 = 4.375g/cm3

Multiple Choice

Frank has an eraser. It has a mass of 4g, and a volume of 2cm³. What is its density?

• 8 g/cm³

• 2 g/cm³

• 1/2 g/cm³

• 24 g/cm³

Multiple Choice

Which liquid is the least dense?

• oil

• water

• syrup 

• plastic bottle

Multiple Choice

What is the volume of Object X?

• 10.0 cm³

• 15.0 cm³

• 20.0 cm³

• 25.0 cm³