Notes
SPI 0807.9.7
Density
Science
Tennessee SPI Objective:
Apply an equation to determine the density of an
object based on its mass and volume
Check for Understanding
Calculate the density of various objects.
Essential Question(s)
What is density? What is mass? What is volume?
How do I calculate density?
How do I multiply and divide with decimals?
Notes
SPI 0807.9.7
Density
Science
What is density?
 Density is the amount of matter (mass)
you have crammed in a given space (volume)
Reminder: mass is how much matter is in an object
 The unit for mass is grams (mg or g or kg)
Reminder: volume is how much space it takes up (size)
 Unit for solid volume is cubic meters (cm3 or m3 or km3)
 Unit for liquid volume is liters (mL or L or kL)
To compute density
 - divide the mass by the volume of the object
Demonstration:
Demonstrate with wadded up paper in a trash can
SPI 0807.9.7
Density
Notes
Science
Density Example:
 Here are two objects that are the same size.
(1) Bowling Ball and (2) Soccer Ball
 One of these objects contains more matter (bowling ball).
 With two same-sized objects like this, the object with more
mass has greater density than the other object.
More Dense
Less Dense
Notes
SPI 0807.9.7
Density
Science
Density Formula
Use this formula: Density = mass divided by volume
M
or
D
=
or Density = volume mass
D= M V
V
Memory Trick
 Soon you will get your first driver’s permit.
 The place where you receive your driver’s permit is
called the DMV (Department of Motor Vehicles)
 Think of DMV for density
D= M V
Quick
Practice
SPI 0807.9.7
Density
Science
Solve the Density Problem Shown Below
Go ahead and use a calculator (for now)
1) Calculate the density of an object with a mass of 25g and a
volume of 10cm3
Example: 25 (mass) divided by 10 (volume) Units…
Density= 10 25
g/cm3
Answer
25g ÷ 10cm3 = 2.5 g/cm3
Don't Forget Your Units!
Example: grams/centimeter cubed
Written like this…g/cm3
Quick
Practice
SPI 0807.9.7
Density
Science
Solve the Density Problem Shown Below
Go ahead and use a calculator (for now)
2) Calculate the density of an object with a mass of 45kg and a
volume of 43m3
Example: 45 (mass) divided by 43 (volume)
Units…
kg/cm3
Density= 43 45
Don't Forget Your Units!
Example: grams/centimeter cubed
Written like this…g/cm3
0807.9.7
Solve The ThreeSPI
Density
Problems Shown Below
Quick
Science
Go
ahead
and
use
a
calculator
(for
now)
Density
Practice
Use this formula: Density=mass divided by volume
or D= M
Density= volume mass
D= M/V
or
V
2) Calculate the density of an object with a mass of 45kg and a
volume of 43m3
Example: 45 (mass) divided by 43 (volume)
(round up to the nearest hundredth)
Density=
3 43 45
3
45kg ÷ 43m = 1.05kg/m
Units…
kg/cm3
0807.9.7
Solve The ThreeSPI
Density
Problems Shown Below
Quick
Science
Go
ahead
and
use
a
calculator
(for
now)
Density
Practice
Use this formula: Density=mass divided by volume
or D= M
Density= volume mass
D= M/V
or
V
1) …density of an object with a mass of 25g a volume of 10cm3?
Example: 25 (mass) divided by 10 (volume) Units…
Density= 10 25
g/cm3
2) …density of an object with a mass of 45kg a volume of 43m3?
Example: 45 (mass) divided by 43 (volume) Units…
Density= 43 45
kg/cm3
3) …density of an object with a mass of 350g a volume of 95cm3 ?
Example: 350 (mass) divided by 95 (volume) Units…
g/cm3
Density= 95 350
Notes
Don't
Forget
Your Units!
SPI
0807.9.7
Example: grams/centimeter cubed
Density
Written like this…g/cm3
Science
Density=mass divided by volume
Answers
1) …density of an object with a mass of 25g & volume of 10cm3?
25g ÷ 10cm3 = 2.5g/cm3
3) …density of an object with a mass of 350g & volume of 95cm3 ?
(round up to the nearest hundredth)
350g ÷ 95cm3 = 3.68g/cm3
Density
In Liquids
SPI 0807.9.7
Notes
Science
Lower
density liquids will float on top of liquids with higher
density
Density
Example: Oil floats on top of water
Designation
Substance
Density
Liquid 01
Water
1.0 g/mL
Liquid 02
Liquid Mercury
13.6 g/mL
Liquid 03
Turpentine
0.8 g/mL
1) Identify which liquids would occupy levels A, B, and C
according to their density.
SPI 0807.9.7 (Density)
ANSWERS
Level A Turpentine (0.8 g/mL)
Level B Water (1.0 g/mL)
Level C Mercury (13.6 g/mL)
Notes
SPI 0807.9.7
Density
Science
Density In Liquids
Lower density liquids float on top of liquids with higher density
Higher density liquids will sink below lower density liquids
View this YouTube Video Clip:
Link: 7-Layer Density Column
SPI
Which cube below
has0807.9.7
the GREATEST density?
Notes
Science
Again…go ahead and
use
a
calculator
(for
now)
Density
(B)
(A)
Mass: 12g
Volume: 3cm3
Mass: 19g
Volume: 7cm3
4 g/cm3
2.71 g/cm3
(C)
(D)
Mass: 11g
Volume: 3cm3
Mass: 23g
Volume: 5cm3
3.6 g/cm3
4.6 g/cm3