
Objectives 
Essential Question:
Is mass in physics the same thing
as the amount of matter present? 
Newton's
3 Amazing Laws

Explain
inertia and its relationship to mass. (mass = linear
inertia)

Explain what is meant by an inertial frame of
reference (Serway p.114).

Solve problems with Newton's 1st law (the
bunny principle).

Explain Newton's second law (F = ma).
This is actually a special case of Newton's 2nd Law. It
assumes that the net force and mass are both constant. We have to introduce momentum to write
the most general case.
 F = net Force or sum of the forces

m = linear inertia

English version: net Force is directly proportional to acceleration

State Newton's 3rd law in 3 ways.
 Serway p.120
 Can't touch without being touched
 Forces always appear in pairs acting in opposite directions
on 2 different objects.

Solve problems using Newton's 3rd law.
Homefun (formative/summative
assessment): Read 5.1 to 5.5

Read:
Insultingly Stupid Movie Physics Chapter
5, Inertia and Newton's first Law: Why Blowing Up a Spacecraft is a Bad
Idea. pp 67  83
Chapter 6, Newton's Third Law: That Special
Hollywood Touch, pp 83  99 
Relevance: Newton's
laws revolutionized science and ushered in a new era of technological
development. Even today over 300 years later they are the foundation of modern
engineering.


Activities 
Lesson 1
Preassessment:
Use the internet to answer questions 21  26 on the Basic
Physics Savvy Quiz
Key Concept: Newton's
laws, free body diagrams.
Purpose:
Solving acceleration problems using free body diagrams.
Interactive Discussion:
Objectives. What would the world be like if Newton's first law
were turned off. In other words, what if motion required a net force
to keep it going. A bus hits a bug. Which has the higher force a bug
or a bus? Draw free body diagrams.
In Class Problem Solving:
 Bob weighs himself on the
elevator.
 Bob pulls himself upward
using a pulley and harness.
 Jane drives her boat.


Essential Question:
If forces always come in pairs,
how can anything move? 
FBDs, g, and Acceleration

Identify action/reaction pairs of forces.

Draw free body diagrams.
 Generally shows the object as a square or a dot.
 Shows only forces from the outside acting on the object.
The forces are shown touching the object.

Never shows forces the object creates on the
outside world.

State 3 ways "g" can be defined.
 Acceleration of a free falling body
with no air resistance on planet Earth =
9.80665 m/s^{2}

Unit
of acceleration. 1.0 g =
9.80665
m/s^{2}

Gravityfield strength
typically used for calculating weight force. On planet Earth g = 9.81 m/s^{2}

Calculate the weight force acting on an object: Fw = mg Note that the g in this case is the strength of the gravity field.

Correctly identify normal forces. Normal forces are forces generated when one surface presses against an object. Normal forces are always perpendicular to the surface causing them.
formative/summative
assessment: vocaulary quiz
Essential Question:
When you step on a
bathroom scale, which force is the scale actually measuring? 
Elevator Problems

Explain which external force acting on a person causes the sensation of
weight. The normal force

Solve elevator problems.
 "g" is a gravityfield strength vector not an acceleration.

"g" is negative because it points downward.

F_{w} = mg

The scale the person stands on
indicates the normal forc not the weight or gravity force
 Solve elevator type problems in a
horizontal dimension. These have 2 opposing
forces in the horizontal dimension. The equation ends up being identical
to the elevator problems.

Solve 2 cable elevator problems.
Here the person
can be visualized as pulling himself up using a rope and pulley.
As is often true, the
trick for solving the problem is drawing a correct FBD.
Homefun (formative/summative
assessment): Read 5.6, prob. 1, 3, 33, 51 pp. 128131

Read:
Insultingly Stupid Movie Physics
 Chapter 10, Acceleration and Newton's Second Law:
How to get started, Use the Breaks, or Change Direction Hollywood Style, pp
147  163
Relevance:
Most engineering majors will be required to take a dynamics course
based primarily on Newton's Second Law. Dynamics analysis is critical
to machine design, an important issue for mechanical engineers .

Lesson
2
Key Concept: Free
body diagrams (FBD)
Purpose: Enable
one to identify the forces that belong in a Newton's second
law equation
Interactive Discussion:
What causes the sensation of weight?
Video Clip:
Show a video clip of the rocket sled ride in
Indiana Jones. Assume Jones weighs 180 lb and is subjected to 10 g
of acceleration as the sled speeds up and 40 g acceleration while
stopping. What would be the size of the force between Jones and his
seat while speeding up? What size force would be required to hold
Jones on the sled while slowing down?
In Class Problem Solving:
elevator problems
 Bob stands on a scale in the elevator
 Bob's boat has water resistance.
 2 cable elevators


Essential Question:
Can metacognition questions be
used to start a problem as well as evaluate its answer? 
Pushing, Pulling, and Cliff Hangers

Find the normal force between objects when one object is pushing another.

Find the tension in the rope when one object is towing another.

Solve Jurassic Park type suspended bus problems.
Metacognition Problem Solving Principle:
A teacher can guide a student to the solution of a complex problem
merely by asking questions, but first the student must first learn to
answer rather than simply follow the teacher's instruction.
Ultimately, the student can solve problems without the teacher by
learning to ask himself or herself the questions.
Problem
solving is about asking questions.
Homefun (formative/summative
assessment): Read 5.6, prob.
31 pp. 128131


Lesson 3
Key Concept: Free
body diagrams (FBD)
Purpose: Enable
one to identify the forces that belong in a Newton's second
law equation
Interactive Discussion:
Objectives.
Video Clip:
Show a video clip of the bus hanging scene in Jurassic Park
In Class Problem Solving:
 Towing problem
 Pushing problem
 Jurassic Park problem


 MiniLab
Physics Investigation (Requires only Purpose,
data, and conclusion)

Title 
Analysis of an Air Track Slider Accelerated by a hanging
weight 
Purpose 
Determine if simple mathematical models can predict the behavior
of an air track slider accelerated by a hanging weight. 
Overview 
 Place the slider on the air track.
 Attach a string to the slider and thread it through a
pulley at the end of the air track.
 Attach a weight to the end of the string so that it hangs
over the table.
 Set up the photogate to measure velocity after the slider
has traveled some distance from a rest position.
By knowing the final velocity and distance the slider's
acceleration can be calculated. Compare this acceleration to one
calculated from theory. Assume the pulley at the end of the
track along with the string pulling the cart are frictionless
and massless. 
Data,
Calculations 
Calculate a % difference between the measured and theoretical
acceleration 
Questions,
Conclusions 
 What is the maximum possible acceleration of the cart?
 If your acceleration values are higher than the maximum
possible, what is the likely source of the error? (Do NOT
claim it's measurement error.)
 Why should the measured value be less than the
theoretical one?

Resources/Materials: 
Air track and slider. Photogates computer system set up with
Vernier LabPro software and Lab Pro units 

Essential Question:
Can we use redefining the x, y axis as a
problem solving strategy? 
Objects on Slopes

Find the normal (F_{wn}) and parallel (F_{wp}) components of the weight force
(F_{w}) for objects on a
slope that makes an angle of with the horizon β.
F_{wn} = F_{w} cosβ
F_{wp} = F_{w} sinβ

Find the angle of the slope where the normal component of weight exceeds the
parallel component.

Solve for acceleration of objects on a slope (zero friction).
Homefun
(formative/summative assessment): 22, 24
pp.128131
Relevance:
Components on a slope is the first step in analyzing numerous real
world problems from ramps for unloading cargo to 4WD vehicle climbing
performance
. 

Lesson 4
Key Concept: Normal
and parallel components on a slope
Purpose: Enable
one to solve slope problems
Derivation: weight components on a slope.
In Class Problem Solving:
 Toto on a slippery slope.
 Tension in Toto's collar
Group problem solving: Plot the
acceleration, normal, and parallel forces vs angle. Draw conclusions
from the plots.
 Box on a slope with angle changing
 Box on horizontal ground being
pushed with angle changing.
 Box on horizontal ground being
pulled with angle changing.
Resources/Materials: 

Formal Physics Investigation 
Title 
Measurement of g Using an Air Track 
Category 
Newton's Laws 
Purpose 
Measure g using an air track 
Models 
kinematic equations, F = ma (Note: if
kinematic equations can be used, then what do you know about the
slider's acceleration?) 
Overview 
A slider can "fall" down the slope of an
air track set at an angle with respect to the horizontal. You are to
devise an experiment for determining the value of g by using the air
track and other equipment provided. 
Safety
Issues 
Air track motors can overheat if the air
inlet is blocked. 
Equipment
Limitations 
Air tracks an their sliders are much more
delicate than they look. Do NOT drop or strike them 
Resources/Materials: 
Air track and slider. Photogates computer
system set up with Vernier LabPro software and Lab Pro units 

Essential Question:
What do civil engineers do? Why
did the Twin Towers collapse? 
Statics (the first half of the story)

State the force conditions required for static equilibrium.
SF_{x }= 0, SF_{y
}= 0, SF_{z }= 0

Solve static equilibrium, cable problems. (buzzard problem)

Solve static slope problems.
Homefun (formative/summative
assessment): prob. 21, 23, 27, 35 pp. 128131
Relevance:
Statics calculations are the first step in designing structures, an
importance issue for both civil and mechanical engineers. 

Lesson 5
Key Concept: Static
equilibrium
Purpose: Solve
static cable problems.
Interactive Discussion: Can
the tension in a rope be greater than a perpendicular force exerted
in its center it?
In Class Problem Solving:
 Buzzard problem
 Stop light problem

