Mass and Volume
Mass
DEFINITION: Mass is how much matter is in an object.
MASS OF A SOLID
To calculate the mass of a solid, use a triplebeam-balance.
Before you place the solid on the triple beam
balance, make sure it is zeroed. If it isn’t, use the
knob on the left to adjust it. Now all you need to
do is place the solid on the balance and adjust
the sliders, starting with the biggest one. Make
sure they click into place! Once the pointer is realigned to zero, add up all the numbers. Now you
have the mass of your solid. The unit of measure
for the mass of solids is grams (g).
Mass
Click on the picture to play with a really
animation about the triple beam balance!
cool
MASS OF A LIQUID
Mass
Since you cannot pour the liquid directly on to the triple-beam-balance,
measuring the mass of a liquid is slightly more complicated. First you need to
find the mass of a container, such as a beaker or a graduated cylinder. Record
the mass.
Next, pour the liquid into the container and take the mass.
To find the mass of the liquid, subtract the mass of the container from the mass
of the container and the water. The unit of measure for the mass of liquids is
grams (g).
Worksheet
Measuring Mass
Volume
DEFINITION: Volume is how much space an object takes up.
VOLUME OF A RECTANGULAR SOLID
To calculate the volume of a rectangular prism, just measure the length,
width, and height of the prism with a ruler, then multiply all three numbers.
Use cm3 as your unit of measure.
Volume = length x width x height
7 cm
=8x5x7
= 280 cm3
5 cm
8 cm
Volume
VOLUME OF A LIQUID
Measuring the volume of a liquid is easy. All you need to do is pour the
liquid into a graduated cylinder. You will see that the water forms a curve
called a meniscus. Read the number on the graduated cylinder that lines
up with the bottom of the meniscus. That number is the volume of the
liquid. The unit of measure for the volume of liquids is milliliters (ml).
Volume
To find the volume of a liquid, pour
the liquid into a graduated cylinder
and read under the meniscus.
The volume in this
graduated cylinder is 43 ml.
Volume
Click on the picture to practice reading different graduated cylinders.
Make sure you have clicked the “PRACTICE” circle.
Volume
VOLUME OF AN IRREGULAR SOLID
If your solid is an unusual shape, you need to
Water Displacement
Method
use the water displacement method. First
pour some water into a beaker or graduated
cylinder and record how much water you have.
Then place your object into the beaker or
graduated cylinder. Record the volume of the
water now.
4.8 ml
5.6 ml
The last step is to subtract the two numbers.
The amount the water went up is actually the
volume of your object. Use cm3 as your unit of
measure.
volume = 5.6 - 4.8
= 0.8 cm3
Volume
If your object floats, use the tip of a pencil
to push it slightly under the water
before reading the volume.
Worksheet
Calculating Volume