Density

Scott Solomon

density

Basics
Density refers to how tightly packed a particular object is.

In the above image, the brick has higher density than the sponge.

You should be given the following formula:
Density = \bf\displaystyle\frac{Mass}{Volume}


Question
A block of wood has a mass of 30 g and a volume of 10 cm³.
What is its density?

Answer
3 g/cm³

Answer Process
See Plug-In.
Mass = 30 g
Volume = 10 cm³

Density = \bf\displaystyle\frac{Mass}{Volume}

Density = \bf\displaystyle\frac{30}{10} = 3

Input Display Comment
clear blinker clears screen
fraction 30 down 10 right \bf\displaystyle\frac{30}{10} Density = \bf\displaystyle\frac{Mass}{Volume}
Plug in 30 for Mass.
Plug in 10 for Volume.
enter 3 Answer
Density


Question
Five blocks of wood have the following properties:
Block 1:  Mass = 30 g; Volume = 10 cm³.
Block 2:  Mass = 28 g; Volume = 4 cm³.
Block 3:  Mass = 26 g; Volume = 13 cm³.
Block 4:  Mass = 24 g; Volume = 8 cm³.
Block 5:  Mass = 22 g; Volume = 11 cm³.

What is the mean (average) density of the five blocks of wood?

Answer
3.4 g/cm³

Answer Process
See Plug-In.
See Mean.

Density = \bf\displaystyle\frac{Mass}{Volume}

Mean = \bf\displaystyle\frac{Sum}{Count}

Input Display Comment
clear blinker clears screen
fraction 30 down 10 right \bf\displaystyle\frac{30}{10} Density = \bf\displaystyle\frac{Mass}{Volume}
Plug in 30 for Mass.
Plug in 10 for Volume.
enter 3 Density Block 1
fraction 28 down 4 right \bf\displaystyle\frac{28}{4} Density = \bf\displaystyle\frac{Mass}{Volume}
Plug in 28 for Mass.
Plug in 4 for Volume.
enter 7 Density Block 2
fraction 26 down 13 right \bf\displaystyle\frac{26}{13} Density = \bf\displaystyle\frac{Mass}{Volume}
Plug in 26 for Mass.
Plug in 13 for Volume.
enter 2 Density Block 3
fraction 24 down 8 right \bf\displaystyle\frac{24}{8} Density = \bf\displaystyle\frac{Mass}{Volume}
Plug in 24 for Mass.
Plug in 8 for Volume.
enter 3 Density Block 4
fraction 22 down 11 right \bf\displaystyle\frac{22}{11} Density = \bf\displaystyle\frac{Mass}{Volume}
Plug in 22 for Mass.
Plug in 11 for Volume.
enter 2 Density Block 5
fraction 3+7+2+3+2
down 5 right		 \bf\displaystyle\frac{3+7+2+3+2}{5} Mean = \bf\displaystyle\frac{Sum}{Count}
enter 3.4 Answer
Density
Mean

 

Practice – Questions
1.  A block of wood has a mass of 35 g and a volume of 10 cm³.  What is its density?
A.  1.5 g/cm³
B.  2.0 g/cm³
C.  2.5 g/cm³
D.  3.5 g/cm³

2.  A block of wood has a mass of 24 g and a volume of 3 cm³.  What is its density?
A.  4.5 g/cm³
B.  5.0 g/cm³
C.  8.0 g/cm³
D.  3.0 g/cm³

3.  A block of wood has a mass of 66 g and a volume of 6 cm³.  What is its density?
A.  11.0 g/cm³
B.  6.0 g/cm³
C.  10.0 g/cm³
D.  1.0 g/cm³

4.  A block of wood has a mass of 108 g and a volume of 12 cm³.  What is its density?
A.  12.0 g/cm³
B.  9.0 g/cm³
C.  8.0 g/cm³
D.  11.0 g/cm³

5.  To the nearest hundredth, what is the mean (average) density of the above four blocks of wood?
A.  31.50 g/cm³
B.  31.51 g/cm³
C.  7.87 g/cm³
D.  7.88 g/cm³


Practice – Answers
1.  D.  3.5 g/cm³

2.  C.  8.0 g/cm³

3.  A.  11.0 g/cm³

4.  B.  9.0 g/cm³

5.  D.  7.88 g/cm³
See Rounding.

 

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