Measuring Measuring

Volume Volume

usingusing the the

MetricMetric System SystemAlice L. Comisky

DefinitionDefinition- the amount of space a substance takes up

VOLUMEVOLUME

In class you can will be measuring the volume of regular rectangular shaped solid objects, irregular shaped solid objects, and liquid substances.

SECTION 1SECTION 1

VOLUME OF A VOLUME OF A REGULAR REGULAR

RECTANGULARRECTANGULARSOLID.SOLID.

VOLUME OF A REGULAR RECTANGULAR VOLUME OF A REGULAR RECTANGULAR SOLIDSOLID

tools: metric ruler

units of measure: cubic centimeter (cm3)-equal to a cube which measures one centimeter by one centimeter by one centimeter

To find the volume of a rectangular shaped object multiply the length of the object by the height and width. Volume = l x w x h

5 cm

10 cm

3 cm

Volume = l x w x h

Volume = 10 cm x 3 cm x 5 cm =

150 cm3

150 cm3

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.

What is the volume of this object, in other words how many cubic centimeters does it contain?

Using the formula Volume = l x w x h you will find the volume to be

Count the number of cubic centimeters in the picture to check your

answer.

12cm12cm33

SECTION TWO SECTION TWO

LIQUID VOLUMELIQUID VOLUME

LIQUID VOLUMELIQUID VOLUME

tools: graduated cylinder

units of measure: liter (L)-this is the basic unit of

volume in the metric systemmilliliter (mL)-this is the unit of measure we use most often in science. 1000 milliliters =1 liter

1 mL is equal to 1 cm3

We use four different size graduated cylinders in science class

100ml 50ml 25ml 10ml

To obtain the most accurate measurement, you want to choose the smallest graduated cylinder possible, based on what you need to measure.

Before reading any graduated cylinder you must first determine what each interval on the cylinder represents.

The space between two major markings on this 100 mL graduated cylinder represents 10 milliliters. Each of these major markings is further divided into 10 smaller intervals. 10 millimeters divided by 10 equals 1. Therefore each interval represents 1 mL.

What level is indicated by the red line?

65mL

The space between two major markings on our 50mL graduate cylinder represent five milliliters.

Each of these major markings is further divided into five smaller divisions. By dividing these numbers you get the value of each smaller interval. 5 divided by 5 is 1. Each small interval on the 50 mL graduate is 1mL.

How many milliliters are in this graduated cylinder?

37 mL

The space between two major marking on the 25ml graduated cylinders represents 5 millliliters. Each of these major markings is further divided into to smaller intervals. 5 milliliters divided by 10 equals 0.5. Each interval represents 0.5mL.

At what level is the red line.

.13.5mL

On the ten milliliter graduate the major markings represent 1 milliliter. Each of these major markings is further divided into 5 smaller intervals. 1milliliter divided by 5 is 0.2 mL

At what level is the red line on each of the following:

72 mL 28 mL 13 mL 6.4 mL

Once you know what each interval marking represents finding the volume of a liquid is easy, all you need to do is pour the liquid into a graduated cylinder and read the volume. Always read the graduated cylinder from eye level.

Each marking on this cylinder represents 1mL. The amount of liquid in the cylinder is 35mL.

You will notice that when a liquid is put into a cylinder, it does something unusual. It curves. This curve is caused by surface tension. When you read the graduated cylinder, you read it at the bottom of the curve. This curve is called the meniscus.

You can clearly see the darker area of liquid, this is the meniscus. Remember to read the level of liquid in a graduated cylinder at the bottom of the meniscus.

50ml51ml

52ml

How many How many milliliters of milliliters of liquid are in this liquid are in this graduated graduated cylinder?cylinder?

Answer: 59 ml

Quick Review

1. What is the basic unit of volume in the metric system?Answer:

liter

2. What unit of volume do we most often use in science class?Answer:

4. When reading the level of liquid in a graduated cylinder you should read the _______of the meniscus.

Answer:

3. What tool do we use in class to measure liquid volume.Answer:

milliliter

graduated cylinder

bottom

5.. What unit of measure is equal to 1cm3

1 mL

SECTION 3SECTION 3

VOLUME OF AN VOLUME OF AN IRREGULAR IRREGULAR

RECTANGULARRECTANGULARSOLID.SOLID.

VOLUME OF AN IRREGULAR SOLIDVOLUME OF AN IRREGULAR SOLID

tools: graduated cylinder

UNITS OF MEASURE:

cubic centimeter (cm3)-equal to a cube which measures one centimeter by one centimeter by one centimeter milliliters (mL)- equal in volume to a cubic centimeter

1. Fill a graduated cylinder with a specific amount of water. (I like to fill it half way.)

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 of the water and the solid.

6. The result is the volume of just the irregular shaped solid.

The volume of just the water is 50 mL.

After the small rock is placed in the cylinder the volume rises to 70mL.

Subtract the 50 mL of water from the combined volume of 70 mL. The rock has a volume of 20 mL.

If you still feel you need practice finding the volume of liquids, regular rectangular shaped solids and irregular shaped solids take the time to stay after school for clinic and practice.

Also, it may be helpful to run through this presentation a second time.

GOOD LUCK!GOOD LUCK! Alice L. Comisky