Welcome to Physics!!
Day One Agenda:
 Intros
 Formalities
 Syllabus: Online!
 Books, Reference Tables
 Tissues = Gold
 What is Physics?
 Unit 1 !!!
Scientific Calculators
► Texas
Instruments = Good
► Casio = Garbage
Target Practice
Mediocre
TI-30XIIS
Best!!
Quiz!
► Doesn’t
Count (except if not complete)
► Try ALL Questions
► See what you know
► Find out what you’ll need to know
Topic Pre-I:
Measurement and Mathematics
Essential Questions
 What do we use to measure Physics?
 How are accuracy and precision different?
 What is scientific notation?
 How can quantities be represented on graphs?
I. Units
A. “Comparison to a known standard”
B. MOST numbers have a unit and they MUST be
written (usually a symbol)
C. The SI System
1. Used everywhere
2. Fundamental Units: Simplest
• Examples: Meters (m)
Seconds (s)
3. Derived Units: put two or more fundamental
units together
• Example:
kilogram • meter
Force =
second2
F = kg • m
s2
= Newtons (N)
4. Prefixes for Units: PRT’s Front Cover!
D. Addition and Subtraction require all quantities to
have the same units
• Example:
200km + 34000m = ?
Should Be:
200 km + 34 km = ?
or:
200,000 m + 34,000 m = ?
II. Measurements, Units, & Instruments
Length (m)
Name of Instrument
Ruler
Mass (kg)
Triple Beam
Balance
Time (s)
Stopwatch/Clock
Force (N)
Spring
Scale
Name of Instrument
Volume (L)
Graduated
Cylinder
Temperature (K)
(°C)
Thermometer
Name of Instrument
Angles (°)
Protractor
Electricity (V)
Voltmeter
or
(A)
Ammeter
III.
AKA: Sig Figs
A. The Rules
PRESERVE
ACCURACY!!
1. All NON-Zero digits are significant
2. Zeros before a nonzero are NOT significant
• 0.005 cm ONE significant digit
• 0.75 cm
TWO significant digits
3. Zeros between two nonzero digits ARE
significant
• 25,001 Ω FIVE significant digits
• 0.203 kg
THREE significant digits
4. Zeros to the right of a nonzero digit ARE
significant if followed by a decimal or are to
the right of a decimal
• 30 sec
ONE
• 10.0 sec
THREE
• 40. sec
TWO
• 3.600 sec
FOUR
5. Correct number of Significant Digits is
always shown automatically when scientific
notation is used
• Example: 2.45 x 108 has 3 sig figs
6. Operations using sig figs
• One Rule: Final answers have the same
number of significant digits as the LEAST sensitive
measurement (lowest number of sig digs)
Example: Sig Fig Operations
► Add:
420 cm
0.515 m
0.80 m
Warm Up #1
► What
1/23/14
is 8.99 x 109 in standard form?
► What is 0.0000000000667 in scientific notation?
► How many megameters are in 5,500,000 m?
► How many kilometers are in 5,500,000 m?
► Which of these is NOT a fundamental unit?
 meters, Newtons, meters per second, kilograms
IV. Precision vs. Accuracy
A. Precise = measurements with great detail
(More decimal places)
B. Accurate = Acceptable, consistent
measurements
(close to the scientifically proven values)
V.
A. Vectors are arrows that represent
actual measurements to scale
• Example: Let 1 meter = 1 centimeter
Therefore: 50 m would be a 50 cm arrow
• The number of a vector is its
magnitude
B. Vectors have both magnitude and direction
• Examples:
 velocity
 force
22 m/s East
45 N at 30o
C. Scalars: values that only have magnitudes
(a certain number of something)
• Examples:
 time
 mass
30 Seconds
100 Kilograms
D. Vector Combination
1. Can involve both addition and subtraction
2. Resultant: A combination of two or more
vectors
3. Vectors are always combined tip to tail
(start of one to end of other)
+
=
Resultant
4. If vectors are acting in different directions, find
the difference in magnitudes and combine tip to tail
to find the direction
 resultant points the same direction as the largest
vector
+
=
Resultant
=?
5. Vectors at angles to each other are still combined
tip to tail!
 angles of vectors must be preserved
 The resultant connects the beginning of the
first vector to the end of the last vector
 Most cases only involve two vectors
 sometimes there can be multiple vectors
involved, but the process stays the same!
Resultant
Resultant
 Graphical vector combination can be done
using metric rulers and protractors!
Warm Up #2
► What
1/24/14
is 4.98 x 109 m in standard form?
► How many gigameters is the above distance?
► How many megameters is the above distance?
► How many kilometers is the above distance?
► How many significant figures are in each of the
numbers below?
 100,000,005 m
8.621 x 103 V
 30.0000 s
200 s
With proper
► Add: 2.3 km, 3500 m, and 4.625 km sig figs!!
Warm Up #3
► Find
1/24/14
the hypotenuse in the following triangle!
10m
18m
► Then
use “trig” to find the angle!
E. Breaking Down Vectors
1. It is MUCH easier to combine vectors using
horizontal and vertical components
2. horizontal component = X component
vertical component = Y component
3. X and Y components can be combined
+
=
All X components are Horizontal
+
=
All Y components are Vertical

4. Diagram of Vector “A”and Components
• x and y subscripts on the components differentiate

them from the original vector A
6. Horizontal and Vertical components make a
right triangle so any side can be found
cosθ = A/H
sinθ = O/H
Adjacent = Ax
Opposite = Ay
Hypotenuse = A
Hypotenuse = A
Ax = Acosθ
Ay = Asinθ
7. Example:
Kyran drags a heavy box with a tensional force 50 N that
acts up to the right at an angle of 40 degrees. What are
the horizontal and vertical components of the force?
Warm Up #4
1/27/14
► Find
the hypotenuse and adjacent side in the
following triangle if the angle θ is 22.6°
?
5m
θ
?
Warm Up #5
1/28/14
► Find
the hypotenuse and opposite side in the
following triangle if the angle θ is 60°
?
?
θ
12m
VI. Scientific Notation
A. Used to express very large and very small
quantities
B. General Form: A x 10n
• A is a number between 1 and 10
• n is a “power” equal the number of places to
move the decimal point
 + for numbers greater than 1
 - for numbers less than 1
C. Adding and Subtracting Sci. Notation
 make the powers of ten (n’s) the same
and then just add (the A’s) together
D. Multiplying and Dividing Sci. Notation
• Rules:
 To multiply, add powers of ten (the n’s)
and multiply the other numbers (the A’s)
 To divide, subtract the powers of ten
(the n’s) and divide the other numbers
(the A’s)
Examples: 100 =
100,000 =
0.001 =
• Addition Example:
2.1 x 105 kg + 8.7 x 104 kg
 Final Answer: 2.97 x 105 kg
• Multiplication/Division Examples:
 Multiply: (1.5 x 105 km) (2.8 x 103 km)
 Divide: (1.5 x 105 km)
(2.8 x 103 km)
E. Estimating Orders of Magnitude
1. Always think in powers of 10
 103 = 1000
101 = 10
100 = 1
10-2 = 0.01
etc.
2. Examples:
• a pencil is closest to _____ kilograms
• the distance from Arlington to
Carrollton is closest to _____ kilometers
VII. The Trig of Physics
A. Right Triangles are used VERY OFTEN in Physics
B. Use the Pythagorean Theorem to solve for the
length of a missing side
• Formula:
c a b
2
2
2
C. Angle Trig
Oscar Had A Heap Of Apples
SOH CAH TOA
 How on Earth do you remember all that???
It’s in the PRT’s!!!
(page 5)
VIII. Graphs
A. Format
B. Vocabulary
• Direct
• Interpolate
• Indirect
• Extrapolate
• Static
• Slope
• Cyclic
• Direct Squared
• Indirect Squared
Energy of a Photon (J)
Frequency (Hz)
E
the slope of the graph is f which means
that the slope is proportional to
h
Force of a Spring (N)
Elongation (m)
Fs
the slope of the graph is x which means
that the slope is proportional to
k
Acceleration (m/s2)
Force (N)
a
the slope of the graph is
which means
F
that the slope is proportional to
1
m
Journal #X
9/10/13
up the symbols on the PRT’s for the variables
shown on the graph below… then show the slope
of the graph using the slope formula.
► Explain the significance of the slope of the graph
► State the relationship shown on the graph along
with the type of relationship.
Potential Difference (V)
► Look
Current (A)