**DENSITY**

**EQ: Can I determine the density of an object using an equation?**

SPI 0807.9.7

SPI 0807.9.7

**What is DENSITY?**

What will happen to an object placed in water if the object’s density is

less

than the water’s density?

DENSITY= The

ratio

of the

mass

of a substance to the

volume

of the substance.

** Density is a

physical property

of matter!!

VOLUME = 2.5 in

MASS = 45.93 g

GOLF BALL vs. PING PONG BALL

VOLUME = 2.2 in

MASS = 2.3 g

Because the golf ball has a

greater mass

, it has a

greater density

.

Density Demonstration

It will FLOAT!!

**Think of density as...**

How much stuff (

mass

) has been packed into a certain amount of space (

volume

)!!

The

more dense

something is, the

more tightly-packed

its atoms are.

The

less dense

something is, the

more space

there is between its atoms.

To calculate density...

Use the following equation:

D = m / v

UNITS:

g/mL

or

g/cm

Sample

Problems

Timothy found a solid metal block that has a mass of 100g and a volume of 25 cm .

What would be the density of the block?

Find the density of a substance with a mass of 28g and a volume of 4cm .

A block of wood has a volume of 10cm and a mass of 50 grams.

What is the density of the block of wood?

M= ?

V= 10 cm

D =10 g/cm

A small plastic toy has a volume of 10 cm and a density of 65g/cm .

What is the mass of the block?

Find the density of a substance with a mass of 27g and a volume of 9cm .

A piece of wood that measures 2cm by 10cm by 4cm has a mass of 80 g.

What is the density of the wood?

What is the density of a rock with a mass of 25g and a volume of 5cm ?

3

3

3

3

3

3

3

3

3

3

3

3

3

The GREATER the object’s

mass

, the GREATER the object’s

density

.

Suppose you have an object whose mass is 20g and whose density is 5.0g/cm³.

Find the volume of the object.

What is the mass of an object that has a volume of 3cm and a density of 4.0g/cm³?

Find the density of a substance that has a volume of 6mL and a mass of 24g.

A block of maple has a volume of 10 cm and a density of 65 g/cm . What is the mass of the block?

3

Find the density of a substance with a mass of 88 g and a volume of 11 cm .

3

Find the volume of an liquid with a mass of 30g and a density of 3.00g/mL.

What is the density of a cube with a volume of 32cm and a mass of 4g?

An object has a volume of 40 mL and a density of 8 g/cm³. What is the mass of the object?

A 16g object occupies 4cm³ of space.

What is the density of the object?

What is the density of a piece of wood that has a mass of 50.0 grams and a volume of 5 cm³?

3

Find the density of a liquid with a mass of 27g and a volume of 3cm .

Find the volume of an object with a mass of 24g and a density of 2g/cm .

Davonte uses the displacement method to find out the volume of a rock. The initial reading of the graduated cylinder was 150 mL. After he dropped the rock in, the water rose to 172 mL.

If the mass of the rock is 88g, what is the density of the rock?

3

A rock is submerged in a beaker that initially contains 50mL of water. After the rock is put into the beaker, the water level reads 75mL.

If the rock has a mass of 50g, what is its density?

3

3