Data
Scientific Method
Uncertainty
1.
Observation
*
units
(metrics)
2.
Define the Problem
* measuring
3.
Test/Experiment
* sig. figs.
4.
Hypothesis
* Data
5.
Collect Data/Manipulate
Manipulation
6.
Conclusion
Accuracy vs. Precision
Accuracy – closeness of results to a standard
Precision – closeness of results to each other
*use same piece of equipment to collect data*
Qualitative
vs. Quantitative
Qualitative – more on precision than accuracy
Quantitative – numbers count and are important
Sig. Figs.
Addition and Subtraction:
*least # places after decimal
Multiplication:
*places after decimal count as sig. figs.
2 . 5
cm = 1 in
Vectors
Vectors
(velocity) – has BOTH
magnitude
and
direction
Scalars
(speed) – has
magnitude
ONLY
*time, mass, volume
Metric System Abbr.
Mm

km

hm

dkm
 m
dm

cm

mm

M
m(E6)

nm(E9)

Mult. Component Vecctors
1.
18m due S
2.
22m, 47deg.
S of W
3.
10 m, 78deg. N of W
4.
30 m due E
*(W&E) Sum of the
Vχ= (0)+ (22 cos47)+(10 cos78)+(30) =12. 9m
*(N&S) Sum of the
Vχ= (18)+ (22 sin47)+(10 sin78)+(0) =24. 3m
*Resultant υ =
((12. 9)
2
+ (24. 3)
2
)
1/2
=27. 5m
* θ
= tan
1
(24. 3)
(12.9)
=
62.0deg
R= 28m, 62deg
S of E

Kinematics
Displacement
If +
it’s AWAY
If
–
it’s TOWARD
Velocity
(m/s)
Use ONLY when
SPEED is CONSTANT
1.
does not include acceleration
2.
does not include starting and stopping
in the same place
v =
χ
t
Acceleration
(m/s/s)
*speeding up or slowing down
a =
v
t
Kinematic Formulas
X Direction
Y Direction
υ = υ
o
+ a t
 g t
χ = χ
o
+ Vo t + ½ a t
2
 ½ g t
2
χ = χ
o
+ ½ (υ + υ
o
) t

υ
2
= υ
o
2
+ 2 a (
χ 
χ
o
)
 2 g (
Change
χ
(o)
to Y(o)
Projectial Motion
Half
*
Y determines time in air
*compliment angles of 45deg have same range
X
.
.
Y
.
χ = V
χ
t
Y = ½ g t
2
T =
χ
Vχ
Full
*
45deg has max.
range
Steps:
1.
υ
o
cos θ
o
/
υ
o
sin θ
o
2.
Find the TIME (check Y)
3.
Find the height / range
X
.
Y
.
χ = V χ
t
t =
2
υ
o
.
(Vx =
υ
o
cos θ
o
)
g
(V
o
=
υ
o
sin θ
o
)
y max =
υ
o
2
2g

Force
(N)

Causes a change in motion (causes acceleration)

Is a VECTOR quantity
Equilibrium
– no acceleration , forces cancel , “at rest”
Newton’s Laws of Motion
1.
An object at rest will remain at rest until acted
upon
by an outside force
INERTIA
– directly related to mass
2.
Acceleration is
directly
related to
Force
indirectly
related to
mass
F = m a
(1 kg m / s
2
= 1 Newton)
3.
Action = equal and opposite reaction
can’t have only one force
F a, b =  F b, a
Normal Force
 able to change until breaking point of
whatever it’s holding
 acts perpendicularly to “holding” object
 comes from ground (except water)
Newtons
1 N = 0. 225 lbs.
Mass is constant
F= ma 
Fw = mg
N
kg
(/ 9. 8)
Kg
N (x 9. 8)
Friction
(Ff)
1.
two or more things must be touching
2.
energy is transferred
(heat, sound, etc)
3.
texture matters… NOT
SURFACE
AREA
μ
=
coefficent of friction
(Ratio of
parallel force to perp. Force)
μ =
F
f
(3 decimal places)
F
N
F
f
= μ m g
Ff = Fw (on flat surface)
μ = tan θ
(when
υ
is constant)
Pressure
:
P =
Force/area
4.
opposes motion which causes decelleration
5.
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 Spring '10
 MichaelGorman
 Physics, Force, Heat, Light, Decibel, color saturation

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