Section 2.1 - CPO Science

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SCIENCE SKILLS 2.1
Chapter Two: Science Skills
2.1 Mass and Volume
2.2 Density
2.3 Graphing
2.4 Solving Problems
Section 2.1 Learning Goals
Explain the meaning of mass and
describe the units for measuring mass.
Distinguish between mass and weight.
Define volume and explain how the
volume of matter is measured.
Investigation 2A
Measuring Mass and Volume
Key Question:
How do you measure mass and volume?
2.1 Measuring mass
Mass describes the amount
of matter in an object.
The SI unit for mass is the
kilogram (kg).
The kilogram is too large a
unit to be convenient for
small masses.
One gram (g) is one-thousandth of a kilogram.
What is the estimated mass of ONE zinc nut?
2.1 Matter
Matter is anything
that has mass and
takes up space.
All matter has mass.
Steel, plastic, rubber,
and glass are
different kinds of
matter.
A car has a lot more of each
kind of matter than a bike.
2.1 Mass and weight are different
 We tend to use the terms mass and
weight interchangeably, but they are
not the same thing.
 Mass is the amount of matter in an
object.
 Weight is a measure of the pulling
force of gravity on an object.
2.1 Mass and weight are different
 A 2.3 kg bag of
flour has a mass of
2.3 kilograms no
matter where it is
in the universe.
 The weight of the
bag of flour is less
on the moon.
The 5 lb bag of flour
on Earth weighs only
.8 lbs on the moon!
2.1 Volume
Volume is the amount of space an object
takes up.
The fundamental unit of volume in SI
is the cubic meter (m3).
More convenient smaller units are
cubic centimeters (cc or cm3), liters
(L) and milliliters (mL).
2.1 Volume
Measuring the
volume of liquids
is easy.
Pour the liquid
into a graduated
cylinder and read
the meniscus at
eye level.
2.1 Displacement
You can find the
volume of an irregular
shape using a
technique called
displacement.
Put the irregularly
shaped object in water
and measuring the
amount of water
displaced.
2.1 Comparing
mass and volume
Mass and volume are two
different properties of
matter.
Size does not always
indicate an object’s mass!
How the matter is packed
into space is more
important.
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