3. measurement (vol. and den.)

7/25/2019 3. Measurement (Vol. and Den.)

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Rejoice, and be exceeding

glad: for great is your reward

in heaven: for so persecuted

they the prophets which were

before you.

Matthew 5:12


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MEASUREMENT: Volumeand Density


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OBJECTIVES

Get the volumes of:

regular and irregular solids;

Compute the density of:regular solids

irregular solids

Liquids

Determine the different devices

used in measuring objects


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VOLUME

VOLUME- is the amount

of space substance can

take up.

Formula:

V = l x w x h


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Use the formula VOLUME = l x w x h, to find the volume

of the following 3 objects. (Objects are not drawn to

scale.)

3 cm

6 cm2 cm

10 cm

2 cm

2 cm

5 cm

10 cm

2 cm

36 cm3

40 cm3

100 cm3

1.

2.

3.


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UNITS OF MEASURE:

cubic centimeter (cm3

)-equal to a cubewhich measures one centimeter by one

centimeter by one centimeter

milliliters (mL)- equal in volume to a

cubic centimeter

VOLUME OF IRREGULAR SOLID


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VOLUME OF IRREGULAR SOLID

1. Fill a graduated cylinder with aspecific amount of water

2. Record the volume of the water.

3. Place an irregular solid into the

cylinder.

4. Record the combined volume of the

water and the solid.

5. Subtract the volume of just the

water from the combined volume ofthe water and the solid.

6. The result is the volume of just the

irregular shaped solid.Subtract the 50 mL of water from

the combined volume of 70 mL.

The rock has a volume of 20 mL.


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Density is defined as mass per unit volume.

It is a measure of how tightly packed and how heavy

the molecules are in an object.

Density is the amount of matter within a certainvolume.

DENSITY


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Density is the Mass per unit Volume

Wood Water Iron

1 cm3 1 cm3 1 cm3

0.50 g 1.00 g 8.00 g

Q) Which has the greatest mass and therefore the most dense?

IRON

DENSITY

= m/v
http://www.cartonionline.com/personaggi/iron_man.htmhttp://www.cartonionline.com/personaggi/iron_man.htm


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1) Find the mass of the object

2) Find the volume of the object

3) Divide : Density = Mass - Volume

To find density:

Ex. If the mass of an object is 35 grams and it takes

up 7 cm3 of space, calculate the density.

Density Equation:

Given: Mass = 35 grams Volume = 7 cm3

Unknown: Density (g/ cm3)

Formula: D = M / V

Solution: D = 35g/7 cm3

D = 5 g/cm3


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Density = Mass

Volume

g or kg

cm3

or m3

g/cm3 or kg/m3

= m

V

Example:

Q) Liquid water has a density of

1000kg/m3

, while ice has density of920kg/m3.

Calculate the volume occupied by

0.25kg of each.

Density Equation:

m

V

V = m = 0.25 = 0.000250m3

1000

V = m = 0.25 = 0.000272m3

920


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DENSITY OF A REGULAR SOLID

Find the Mass ofthe solid on abalance.

Measure the threelengths andcalculate theVolume.

(V = l x w x h ) Calculate the

Density.4.0 cm

2.0 cm

3.0 cm

= m = 240 =10.0 g/cm3

V 24

m = 240 g


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DENSITY g/cm3

Aluminum 2.70

Iron 7.86

Brass 8.50

Wood 0.50

Slate 2.90

Glass 2.50


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DENSITY OF AN IRREGULAR SOLID

Find the Mass of the solid ona balance.

Fill the Measuring Cylinderwith Water to a knownVolume.

Add the Object.

Work out the Volume ofWater that is displaced.

Calculate the Density.

50 cm3

80 cm3

m = 360 g = m = 360 =12.0 g/cm3

V 30


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DENSITY OF AN IRREGULAR SOLID

OR use a Eureka Can to find the Volume. Find the mass of the solid on a

balance.

Add water until just overflowing. Place a Measuring Cylinder under

the spout.

Add the Object.

Collect the Water and read off

the Volume.

Calculate Density

m = 440 g

40.0 cm3

= m = 440 =11.0 g/cm3

V 40


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DENSITY OF A LIQUID

Find the Mass of an empty MeasuringCylinder.

Add a certain Volume of Liquid.

Find the Mass of the Measuring

Cylinder and Liquid Calculate the Mass of Liquid.

How?

Calculate Density of Liquid.

25.0 g

20.0 cm3

45.0 g

45 25 = 20 g

= m = 20 =1.00 g/cm3

V 20

Mass of Liquid = Mass of Measuring Cylinder and LiquidMass of empty Measuring Cylinder


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Change Mass AND Keep Volume Same

Ways to Affect Density

Which container has more density?

Increase the mass increase density

Decrease the mass decrease in density


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Ways to Affect Density

Change Mass AND Keep Volume Same

Which container has more density?

Increase the volume decrease density

Decrease the volume increase in density


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What 2 ways will INCREASE density?


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What 2 ways will INCREASE density?

Keep thesame

mass AND

decrease

thevolume

Keep the

samevolume

AND

increase

the mass


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Liquid Layers

If you pour together liquids that dont mix andhave different densities, they will form liquid

layers.

The liquid with the highest density will be on the

bottom. The liquid with the lowest density will be on the

top.

Objects or substances with MORE density will

sink below objects or substances with LESSdensity

Which do you think is MORE dense,

Water or Oil???


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Water, Oiland a SuperballThe oil is less dense than the water, so its on top. The superball is lessdense than water, but more dense than oil, so it sinks to the bottom of

the oil layer, yet floats on the top of the water layer.


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The density of five liquids are measured as

follows:

Liquid 1: 1.0 g/mL

Liquid 2: 1.38 g/mL

Liquid 3: 0.77 g/mL

Liquid 4: 2.95 g/mL

Liquid 5: 0.056 g/mL

Liquid 5

Liquid 3

Liquid 1

Liquid 2

Liquid 4


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Liquid Layers

Check out this picture. Which layer

has the highest density?

Which layer has the lowest

density?

Imagine that the liquids have thefollowing densities:

10g/cm3. 3g/cm3.

6g/cm3. 5g/cm3.

Which number would go with

which layer?10 g/cm3

3 g/cm3

6 g/cm3

5 g/cm3


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Liquid Layers

Try on your own!

Imagine that the

liquids on the right

have the followingdensities:

15g/cm3 10g/cm3

3g/cm3 9g/cm3

7g/cm3 12g/cm3

Match the colors to

the correct densities.

3g/cm3

7g/cm3

9g/cm3

10g/cm3

12g/cm3

15g/cm3


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Liquid Layers

Which layer has the highest

density?

Which layer has the lowest

density?

Imagine that the liquids have thefollowing densities:

10g/cm3. 3g/cm3.

6g/cm3. 5g/cm3.

Which number would go with

which layer?10 g/cm3

3 g/cm3

6 g/cm3

5 g/cm3


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Measuring Devices

Measure of Weight-physical quantity thatcharacterizes an amount of matter (mass)

that is measured by means of scale.


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Measuring Devices for Mass

1. Beam Balance

compares the mass of a

body with that of

another body knownmass.

when the two pans

hanging from a bar

(beam) are in balance,

the two weights are

equal


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2. Analytical balance

used specially in the

laboratory for takingvery precise weight

measurement.


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3. Bathroom Scale

used for weighing aperson

it has a springmechanism thatcompresses inproportion to the

weight


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4. Electronic Scale commercial scale that

weighs and calculates

the price of a quantityof merchandise.


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Measuring Device for Mass

5. Spring Balance

scale made of a hook

attached to a spring

that stretches inproportion to the

weight of the object

being weighed.


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Triple Beam Balance


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Measuring Devices for Volume

Volumetric Measuremento Plays a central role in the laboratory

o determines the degree of accuracy required for

each measurement


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Measuring Devices for Volume

2. Graduated

Cylinder (5-2000 mL)

used to measure liquid

contained in them

has accurate volume

when it reaches the

corresponding markingon the scale


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TRY IT OUT!

1. A box has a top area of 1.92 m2 and a height of 1.2 m.

What is the volume of the box?

2. The area of one square face of a cube is equal to 64 cm2

.Find the volume of the cube.

3. A box has a length of 24 cm, a width of 12 cm and a height

of 7 cm. What is the area of the top of the box and the

volume of the box?

4. A box has a length of 1.6 m, a width of 92 cm and a height

of 1.2m. What is the volume of the box in m3?


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TRY IT OUT!

5. Frank has a paper clip. It has a mass of 9 g and a volume

of 3 cm3. What is its density?

6. Frank also has an eraser. It has a mass of 3g, and a volumeof 1 cm3. What is its density?

7. Jack has a rock. The rock has a mass of 6g and a volume of

3 cm3

. What is the density of the rock?

8. Jill has a gel pen. The gel pen has a mass of 8g and a

volume of 2 cm3. What is the density of the gel pen?


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TRY IT OUT!

9. Mercury is a liquid metal with a mass density of 13.6g/cm3. What is the mass of 10.0 cm3 of mercury?

10. Two blocks are on a table. Block A has a volume of 30.0

cm and a mass of 81.0 g. Block B has a volume of 50.0 cm

and a mass of 135 g. Which block has the greatestdensity?

DENSITY g/cm3

Aluminium 2.70

Iron 7.86

Brass 8.50

Wood 0.50

Slate 2.90

Glass 2.50

3. measurement (vol. and den.)

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