Transcript volume

Measuring
Volume
using the
Metric System
Alice L. Comisky
VOLUME
Definition- the amount of space a
substance takes up
In class you can will be
measuring the volume of
regular rectangular shaped
solid objects, irregular shaped
solid objects, and liquid
substances.
SECTION 1
VOLUME OF A REGULAR
RECTANGULAR
SOLID.
VOLUME OF A REGULAR RECTANGULAR
SOLID
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
150 cm3
10
cm
Volume = l
x
w
x
h
3
150
cm
Volume = 10 cm 3 cm 5 cm =
x
x
3 cm
Use the formula VOLUME = l x w x h, to find the
volume of the following 3 objects. (Objects are not
drawn to scale.)
1.
3.
3 cm
36 cm3
6 cm
2 cm
100
cm3
10 cm
5 cm
2 cm
2.
2 cm
40 cm3
10 cm
2 cm
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 12cm3
Count the number of cubic centimeters in the picture to check
your answer.
SECTION TWO
LIQUID VOLUME
LIQUID VOLUME
tools: graduated cylinder
units of measure:
liter (L)-this is the basic unit of
volume in the metric system
milliliter (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.
How many
milliliters of
liquid are in this
graduated
cylinder?
52ml
50ml
51ml
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: milliliter
3. What tool do we use in class to measure liquid volume.
Answer: graduated cylinder
4. When reading the level of liquid in a graduated cylinder you should
read the _______of the meniscus.
Answer: bottom
5.. What unit of measure is equal to 1cm3
1 mL
SECTION 3
VOLUME OF AN
IRREGULAR
RECTANGULAR
SOLID.
VOLUME 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.
The
volume
of just
the
water is
50 mL.
After the
small
rock is
placed in
the
cylinder
the
volume
rises to
70mL.
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.
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!
Alice L. Comisky