What is physics?
Study of the interaction between matter
and energy
 Physics is not always obvious

 Do the test video
Determining the laws of physics



Scientists observe nature and develop
conceptual and mathematical theories
that describe their observations
Science is driven by nature itself, and
nature gives us no choice
As new information is obtained
scientific theories can be proved
wrong or modified
Why study physics?
To fully understand the workings of the
universe and our everyday world, we
must understand physics.
 Physics is the most basic science and
can be found in all areas of academics.

Eight Reasons
Units in physics
Base Quantity
Base Unit
Length
Mass
Time
Show importance of units video
Symbol
Why is it important to have an
agreed upon system of measure?
Converting with the metric
system
Dimensional Analysis
Used for converting similar measurements to
make comparisons
 Examples

 Convert 1 month to seconds
 Convert 11 m/s to mph
Dimensional analysis practice problems
Measurements

All measurements have some uncertainty and
will contain some error
•
•
The significance of the measurement is determined by the
number of divisions on the measuring device
Measure the line below
Parallax
Precision versus Accuracy
Determining the amount of
error
Significant Digits
Count the number of significant digits

0.00123 ~

1.340 ~

2.00123 ~

101 ~

1200 ~

1.00 ~

1.34 ~

1.00 x 106 ~
Rounding
Round to two significant digits

22.51 =

22.5 =

23.49 =

23.5 =

19.7 =
Operations Using Significant
Digits
Why use Scientific
Notation?

Start with a $100 dollar bill. Currently the largest U.S.
denomination in general circulation.
Why use Scientific
Notation?

A packet of one hundred $100 bills is less than 1/2" thick and
contains $10,000.
Why use Scientific
Notation?

This next little pile is $1 million dollars (100 packets of $10,000).
Why use Scientific
Notation?

$100 million fits neatly on a standard pallet.
Why use Scientific
Notation?

1 billion dollars.
Why use Scientific
Notation?

1 trillion dollars.
Scientific Notation
Fermi Problems

How many students attend this high
school?