the SI unit is the kilogram , a multiple
of the ram . but we sometimes use
multiples or submultiples of the unit
. To obtain submultiples of a kilogram
, we multiply by a factor of 10
volume
volume
is the
space
that a
body
occupies
the SI unit is the
cubic metre , to
obtain its multiples
and submultiples ,
we divide or multiply
by a factor of 1000
capacity
capacity
indicates the
amount of
space that a
container has
the SI unit
is the litre
, witch is
equivalent
to 1dm3.
the factor
is 10
matter and its measurement
matter
the object of study for natural science is
matter
is everyting that occupies space and has mass
physical quantities
some characteristics of matter are easy to
describe because we can observe and
measure them
a physical quantity is any property of matter that can be
measured , like the mass or size of a body
properties of matter that are subjective or cannot be
measuredare not physical quantities
measurement
to measure a physical quantity , we
need to establish a standard of
measurement that we can use to
make comparisons with other
examples. This standard is called a
unit
the international system of units
in the past , were many different units of
measurement.
the rest of the units are derived from these base units
and are called derived units
length and surface area
length is a physical quantity that
expresses a distance between two
points
the SI unit of length is the metre (m) but we
sometimes use multiples or submultiples of
the unit
To obtain multiples, we have to multiply or
divide by a factor of 10
length
surface area
the external part of a body is called the surface
to measure a surface , we need to
work out this area
the SI unit is the square metre . To obtain multiples and
submultiples , we have to multiply or divide by a factor
of 100
properties of matter
extensive poperties
they depend on the
amount of matter there is
intensive properties
they do not depend on
the amount of matter
intensive properties help us to
differenciate between different types
of matter
density
is an intensive
property
density is he quoetient of mass and volume . If the density
is high , the body is heavy . If the density is low , the body is
light . its formula is : d= m/v
the SI unit is the kg/m3 , but it can also be expressed in g/cm3
general properties
they do not depend on
the substance
specific properties
they depend on the
substance
two different substances can have the same
general properties , but the can not have the same
specific properties do not depend on the size of
the body.