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You see and touch many things
each day. You can describe them using your 5 senses.
Such things as the water we use to shower each morning, the food we eat
each day, the clothes we wear, the books we use at school and even
the air we breath, all have something in common. They are all matter.
Matter is anything that takes up space (volume) and has mass. Matter
is what every thing in the universe is made of, including us.
Physical properties are used to describe the things around us, all of which
are made out of matter.
Physical Properties are characteristics of a substance that can be observed without changing the identity of a substance. Physical properties are further subdivided into two classifications, general properties and specific properties. General properties describe characteristics
that all forms of matter have in common. Some examples are; mass,
weight, volume, and density. Mass is the amount of matter in
an object. Mass is measured in metric units called grams using a
scientific measurement tool called a balance.
When using a balance to determine
the amount of the matter in an object, we compare the mass of the object
with the known mass of other objects. This process is called, massing
an object.
Volume is the amount of space
an object takes up or fills. There are two scientific measurement
tools used to determine volume, metric rulers and graduated cylinders.
The metric ruler measures distance in units called meters. It is
the tool used to measure the volume of objects that are regularly shaped
Boxes, sugar cubes, ice cubes, and swimming pools are a few examples.
See if you can think of three or four other examples.
If you wanted to know the volume of a sugar cube, you would measure each side and find that each side is 1 centimeter (cm) long. The formula used to determine volume is (Volume = Length x Width x Height) or V = L x W x H. If you own a lap pool and want to know how much water it will take to fill it, you must measure the length, width, and depth of the lap pool. When you measure the lap pool you find that it is 10 meters long, 5 meters wide, and 1.5 meters deep. What volume of water will you need to fill your lap pool?V = 1cm x 1cm x 1cm The answer is in meters cubed or cubic meters. Meters x meters x meters is equals to m3 just as 5 x 5 x 5 is equals to 53.V = L x W x H A graduated cylinder or beaker
is used to measure liquid volumes and the volumes of irregularly shaped
solid objects such as a gold ring. The liter (l) is the metric
unit for liquid volume. What can you think of that is measured in
liters? The amount of water in a rain drop would be measured in units
called milliliters (ml).
The volume of an irregularly
shaped object is determined using the displacement method and a graduated
cylinder. Any object lowered into the liquid in a graduated cylinder
will push a volume of the liquid out of the way so there is room for the
object. The level of the liquid in the graduated cylinder will rize.
Weight is a measure of the gravitational
force exerted on the mass of an object. In order to understand weight
you msut have a good understand of gravity. Gravity is a force of
attraction between objects that is due to their masses. The amount
of gravitational attraction between two objects depends upon two things,
the distance between the objects and the mass of the objects. The
greater the mass of the objects the greater the gravitational attraction.
This is known as a direct relationship. When mass increases,
gravitational attraction increases. When mass decreases gravitational
attraction decreases. The greater the distance between objects less
the gravitational attraction. This is known as an indirect relationship.
When distance increases, gravitational attraction decreases. When
distance decreases, gravitational attraction increases.
The metric unit for weight is Newton (N). One N is equal to 1 kg x 1m/s/s or 1 kg x m/s/s. |
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