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Calculating Density
Class Practice
The Formulas
O To calculate the volume of a regular shaped solid
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you must multiply length X width X height
Density = mass ÷ volume also written out
Density = mass/volume
Mass = density X volume
Volume = mass ÷ density
O When ever the # for mass is given (some version
of grams) grams goes in the calculator first
because she was born first (hint hint). No matter
if you are finding volume or density.
Step One
O You must first read the question to see if they
want you to find mass, volume or density.
O If it’s volume they will give the mass and the
density
O If it’s density the question will give you the mass
in g and the volume in mL or cm3. (The answer
for density will be in g/cm3 for solids and g/mL
for liquids).
O If it’s mass the question will give you the density
and the volume.
Step Two
O Write out the equation
O Mass = #density X #volume
O Density = #mass ÷ #volume
O Volume = #mass ÷ #density
O Then do the math.
O Let’s try a few. You can use the notes you
just took.
Try number 1
O A student measures the mass of an 8 cm3
block of brown sugar to be 12g. What is the
density of the brown sugar?
The mass and the volume are given.
What does the question ask you to calculate?
Write the math equation you will need to solve
on your board.
Now do the math and write the answer on your
board.
Try Number 2
O A chef fills a container up to the 50 mL line
with 43g of oil. What is the density of the
oil?
O First write on your board the word for what
the question wants you to find.
O Now write out the equation you will solve
O Now do the math and write the answer on
your board.
Try Number 3
O If a perfect cube with a mass of 176g measures
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4cm in every direction what is the density of the
cube.
What two things must you know to find the
density of an object?
How do you find the volume of a regular shaped
solid?
Write out the math to find the volume of this
solid. Then do the math.
Now find the density using the mass that was
given and volume you calculated. Write that on
your board.
Try Number 4
O Calculate the mass of a liquid with a density
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of 2.5 g/mL and a volume of 15 mL.
What does the question ask you to find?
What is the basic equation for finding this
value?
What is the math equation for finding that
value for THIS question?
Now do the math and write your answer on
your board
Try Number 5
O A block has a mass of 43 g and a density of
1.3 g/cm3. What is the volume of that
block?
O What is the basic equation for finding
volume?
O What is the equation for finding the volume
of THIS block?
O Now do the math and write your answer on
your board.
Try Number 6
O The density of a rock is .87 g/cm3 and it’s
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mass is 32 grams. What is the volume of
the rock?
What is the problem asking you to find?
What is the basic equation for finding that?
What is the equation for finding that for THIS
rock?
Do the math and write your answer on your
board.
Try Number 7
O A unknown liquid has a density of 3.2 g/mL
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and a volume of 42 mL. What is the mass
of the liquid?
What is the problems asking you to find?
What is the equation for finding that?
What is the equation for finding that for THIS
liquid?
Now do the math and write your answer on
your board.
Try Number 8
O An unknown solid has a volume of 36 cm3 and a
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density of 1.6 g/cm3. What is the mass of the
solid?
What is the question asking you to find?
What is the basic equation for finding that
answer?
What is the equation for finding that for THIS
solid?
Now do the math and write your answer on your
board.
Try Number 9
O A plastic car has a density of .67 g/cm3 and
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a volume of 11 cm3. What is the mass of
the plastic car?
What is the question asking you to find?
What is the basic equation for finding that?
What is the equation for finding that for THIS
plastic car?
Now do the math and write your answer on
your board.
Table of Densities
Solid Type
Density g/cm3
Solid Type
Density g/cm3
Marble
2.56
Copper
8.92
Quartz
2.64
Gold
19.32
Diamond
3.52
Platinum
21.4
Try Number 10
O While digging in the backyard, you find an old
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coin. Its mass is 26.76 g and its volume is 3
cm3. What is the old coin made from?
First, what must you find to use the chart to find
out what it is?
What is the basic equation for finding that?
What is the equation for finding that for THIS
coin?
Do the math and write your answer on your
board.
What was your coin made of?
Table of Densities
Solid Type
Density g/cm3
Solid Type
Density g/cm3
Marble
2.56
Copper
8.92
Quartz
2.64
Gold
19.32
Diamond
3.52
Platinum
21.4
Try Number 11
O You think you have found a diamond. Its
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mass is 5.28g and its volume is 2 cm3.
What do you need to know about this thing
to use the chart to see what it really is?
What is the basic equation for finding that
out?
What is the equation for that for THIS item?
Now do the math and write it on your board.
What was your item made
from?
Table of Densities
Solid Type
Density g/cm3
Solid Type
Density g/cm3
Marble
2.56
Copper
8.92
Quartz
2.64
Gold
19.32
Diamond
3.52
Platinum
21.4
Try number 12
O There is a paper weight on the teacher’s desk.
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Its measurements are 3 cm by 4 cm by 6 cm.
The paper weight has a mass of 184.32 g.
What do you have to know to calculate density?
What is the math you must do to find the volume
for this block? Write your answer on your board.
Now what is the equation for finding the density
of THIS paperweight?
Do the math and write your answer on your
board.
What is the paperweight made
of?
Table of Densities
Solid Type
Density g/cm3
Solid Type
Density g/cm3
Marble
2.56
Copper
8.92
Quartz
2.64
Gold
19.32
Diamond
3.52
Platinum
21.4
Try Number 13
O You find a ring with a mass of 107 g. You fill
a graduated cylinder up with 10 mL of water
and put the ring in the cylinder. The water
rises up to the 15 mL mark. What is the
volume of the ring? What is the density of
the ring? Write your answer to both of those
on your board.
What was the ring made of?
Table of Densities
Solid Type
Density g/cm3
Solid Type
Density g/cm3
Marble
2.56
Copper
8.92
Quartz
2.64
Gold
19.32
Diamond
3.52
Platinum
21.4
Rank these on your board from
least dense to most dense.
Table of Densities
Solid Type
Density g/cm3
Solid Type
Density g/cm3
Marble
2.56
Copper
8.92
Quartz
2.64
Gold
19.32
Diamond
3.52
Platinum
21.4