Review
Significant Figures, Vector Math
Velocity, Acceleration, Force
A Scientific Method
Accuracy and Precision
Accuracy – How close to the actual value
Precision – How close to each other.
A measurement of 4cm 1cm is the same as 3cm to 5cm
Significant Figures
Multiplication vs. Addition

Each group take one of each measuring
device (ruler, paper, and paper clip).
Measure three objects and sum the results.
Discuss the accuracy of your results. Explain
how the measurement with the least
significant figures affects your final result.
Significant Figures
Multiplication vs. Addition

Addition




43.8
+5.67
49.4
Multiplication



43.8
x5.67
248.
Variables
Dependant – subject of the experiment
 Independent – The controlled variable


E.G. How does speed of a sail boat change
with wind?
The speed of the sail boat is dependent on the
wind.
 The wind is independent of the speed of the sail
boat.

Conversions
3Km
1000m
1hr
1 min
___m
hr
1Km
60 min
60 sec
___s
Conversions

A mass of 300 grams is
accelerated at a rate of
1km per minute.
(F=ma)
300g g km
Minute^2
1Kg
1000g
(1 min)^2
(60 secs)^2
A Newton is a
1000 m
1 Km
kg gm
s2
___kg g m
___s^2
Distance vs. Displacement

Distance is the sum of the segments of the
path, regardless of direction.

Displacement is the straight-line distance
from the point of origin to the ending point.

Make a graph. Draw a line over to 3x and
another line up to 4y. Determine the
displacement and the distance.
Vector vs. Scalar

Scalar has magnitude
4

seconds
Vector has magnitude and direction
 5m/s
East
Relationships

Directly Proportional
 x=2y

Inversely Proportional
 x=1/2y

Exponentially Proportional
 x=y^2
Graph
Average Velocity

The slope on a position-time graph is
velocity (displacement divided by time).
Position vs. Time
Average Acceleration

Average acceleration is the slope on a
velocity-time graph.
Velocity vs. Time
slope 
v
t
a
v
t
Position,
Velocity, and
Acceleration
d
slope 
t
v
slope 
t
Horizontal and Vertical
Components of Motion
Equations with respect to the vertical component (y):
v f  vi  at
1 2
y  vi t  at where y  d f  di or height
2
2
2
v f  vi  2ay

Solve for delta y in terms of the
vertical components of vf and vi
y 

Solve for t in terms of the
vertical components of delta y,
and v
t
Horizontal and Vertical
Components of Motion

Virtual Lab
 Cannon
Exercise
 Juggling Exercise
Horizontal and Vertical Projectiles
Force

www.HowStuffWorks.com

“How Force, Power, Torque, and Energy Work”
Forces on an Object
Tension
Friction
Sled
Feet
Friction
Newton’s First Law

A body continues to maintain its state of rest
or of uniform motion unless acted upon by
an external unbalanced force.
Motion and Newton’s Second Law
Force equals mass times acceleration
Net Force
Net force is the force associated with
acceleration (F=ma).
 Net force is the sum of all forces acting on a
system.

 If
the forces acting on a system do not cancel each
other (add to a non-zero result, that is, are not in
equilibrium), the system undergoes acceleration in
the direction of said force.

Note: Equilibrium means that there is a net force of zero
(no acceleration).
Weight and Normal
Force
Forces on an Inclined Plane
Forces on an Inclined Plane
Newton’s Third Law: Interaction Pairs
To every action there is an equal and opposite reaction.
Vector Components
Vector Components
Forces on an Inclined Plane
Surface and Friction
Static Friction
Trajectory of a Projectile
Horizontal and Vertical
Components of Motion
Which component directly determines time
in the air?
 Which component directly determines
distance traveled

Relative Velocity
Relative Velocity
Angular Velocity

How fast an angle is traversed.
Circular Motion
Angular Velocity
Circumference
 Period
 Frequency
 Centripetal Acceleration

Centripetal Force

A centripetal force is not a new type of
force; rather, it describes a role that is
played by one or more forces in the
situation, since there must be some force
that is changing the velocity of the object.
For example, the force of gravity keeps the
Moon in a roughly circular orbit around the
Earth, while the normal force of the road
and the force of friction combine to keep a
car in circular motion around a banked
curve.
Angular Acceleration
Car Experiment – Virtual Lab
 Merry-go-round Experiment – Virtual Lab
