Density and Volume

Density

Matter is anything that has mass and volume(takes up space).

Density is a measure of mass per volume.

The upward force that a liquid or gas exerts on a
body floating in it.

Buoyancy

How does density relate to buoyancy?

If an object/substance is less dense than a
fluid that surrounds it, it will float!

Air is a fluid

Water is a fluid

Any liquid or gas is a fluid!

If an object is less dense than water, it will float on water.

Olive oil is less dense than water,
so It floats on top.

Sand is more dense than water, so it
sinks!

Block 1

Block 2

Block 3

Compare the density of each block to water.

Higher, lower, or the same?

Labelling

Label which liquid would be most dense and less dense

Drag labels to their correct position on the image

More density

Less density

Bubbles of air float in
water because they are
less dense than water.

If an object is less dense than air, it will float in air.

A helium balloon is
less dense than air.

An airship is less dense than air.

Why does a giant ship float in the ocean
but a small rock sink?

An object will float in water if it is
less dense than water!

A ship is less dense than water, the
rock is not.

The space taken up by the
ship is largely rooms filled
with air.

•.

What weighs more, a tonne of feathers or a tonne of
bricks???

Neither, both
weigh a tonne!!!

But…
Bricks are more
dense!!!

Poll

Which weighs more?

• A tonne of feathers

• A tonne of bricks

• A tonne of bricks and feathers are the same

•.

Working out the density of an object.

The density of something is its mass per unit of volume.

The density of water is approximately 1000 kg/m3 and the
density of air is approximately 1.2 kg/m3

Density in g/cm3or g/mL
Mass in g
volume, in cm3or mL

density = mass ÷ volume

To work out density we need to know…

MASS

VOLUME

density = mass ÷ volume

weigh the object

how do we calculate volume?

Multiple Choice

What is the formula for density?

• density = mass x volume
• density = mass / volume
• density = mass + volume
• density = mass - volume

Calculating Volume

volume = length × width × height

1. Calculate the volume of the following shapes:

Multiple Choice

Find the volume of the rectangular prism

• 12 ft²

• 12 ft³

• 16 ft³

• 64 ft³

Multiple Choice

Find the volume of the rectangular prism

• 80 m³

• 80 m²

• 40 m²

• 40 m³

Multiple Choice

Find the volume of the rectangular prism

• 10 cm²

• 30 cm³

• 12 cm²

• 24 cm³

Not all objects have regular volumes that are
easy to measure!

How could we work out the volume of this object?

A ‘eureka can’ can be used to determine the volume of oddly
shaped objects.

The volume of the object is
equal to the volume of the
water that is forced through
the spout.

Calculating volume

•.

Activity Time!!!

Multiple Choice

A block of wood has a mass of 2g
and a volume of 1cm3. Calculate
the density of the block of wood.

d=m/v

• 2g/cm3

• 4g/cm3

• 2cm3/g

• 1cm3/2g

Question:

A rock of wood has a mass of 9g
and a volume of 3cm3. Calculate
the density of the rock.

d = m ÷ v

d = 9 ÷ 3

d = 3g/cm3

density = mass ÷ volume

1. 1000g of water has a volume of 1cm3. What is the density of water?
Calculate Density

2. A rock has a mass of 1g and a volume of 2cm3

3. A box has a mass of 10g and a volume of 5cm3

4. A crate has a mass of 90g and a volume of 30cm3

6. A boat has a mass of 200g and a volume of 4cm3
5. A cupboard has a mass of 110g and a volume of 11cm3

1000g/cm3

0.5g/cm3

2g/cm3

3g/cm3

10g/cm3

50g/cm3

7. An object displaces 24cm3 of water and has a mass of 48g
8. An object displaces 50cm3 of water and has a mass of 100g
9. A rectangular prism has sides of length 2cm, 3cm, and 4cm
and weighs 48g. Calculate density.
10. A rectangular prism has sides of length 3cm, 4cm, and 5cm
and weighs 240g. Calculate density.

2g/cm3

2g/cm3

2g/cm3

4g/cm3

d = m ÷ v

Multiple Choice

What is the volume of the liquid?

• 6.5

• 6.7

• 6.6

• 66

Open Ended

In your own words describe how you would find the volume of the rock in the picture. Write in complete sentences with correct grammar and punctuation.

Match

Match the unit measurement that would be used to find the density of the objects in each picture.

g/cm3

g/mL

g/mL

g/cm3

• g/cm3

• g/mL

• g/mL

• g/cm3

Categorize

Options (6)

wood- .6 g/cm3

Ice .9 g/cm3

Styrofoam .01 g/cm3

quartz 2.5 g/cm3

Aluminum 2.70g/mL

Gold 19.3 g/mL

Freshwater has a density of 1g/mL. Place each of the following objects into the correct category if they were placed in water?

Sink

Float

Multiple Choice

Which statement is true about this picture?

• The dish soap is more dense than the honey

• The cherry tomato is more dense than the milk

• The honey is less dense than the bolt

• The water is less than the lamp oil

Multiple Choice

An object's mass is 12 g and its volume is 4ml. What is the density?

• 4 g/ml

• 16 g/ml

• 3 g/ml

• 6 g/ml

Multiple Choice

When an object floats in water it pushes some water out of the way. This is called...

• Replacement

• Displacement

• Tidal waves

• Making space

Multiple Choice

Who was the first person to connect displacement of water with buoyancy?

• Mr. Müller

• Plato

• Archimedes

• Picasso

Multiple Choice

Which object has the highest density in this picture?

• A

• B

• C

1. 500kg of a liquid has a volume of 2m3.
Calculate Density

2. A stone has a mass of 30kg and a volume of 5m3

3. A box has a mass of 100kg and a volume of 20m3

4. A crate has a mass of 870kg and a volume of 30m3

6. A car has a mass of 400kg and a volume of 80m3
5. A cupboard has a mass of 510kg and a volume of 3m3

250kg/m3

6kg/m3

5kg/m3

29kg/m3

170kg/m3

5kg/m3

7. An object displaces 240m3 of water and has a mass of 480kg
8. An object displaces 500m3 of water and has a mass of 2000kg
9. A rectangular prism has sides of length 3cm, 5cm, and 7cm and weighs
315g. Calculate density.
10. A rectangular prism has sides of length 11cm, 12cm, and 15cm
and weighs 11,880g. Calculate density.

2kg/m3

4kg/m3

3g/cm3

6g/cm3

d = m ÷ v

Word Cloud

What are some key words from today's topic?