Essential Question:
What is the fastest way to swim across a swiftly flowing river? 
Mathematical Vector Addition

State the relationship between the magnitudes of
vector components that exist in different dimensions (such as the x and y dimensions). They are totally independent of each other. Different dimensions are like separate worlds.

State the relationship between the direction of
vector components in different dimensions. They are at a 90 degree angle with each other.

Add
vectors together using the component method.

Make a vector diagram showing all the vectors with their tails at the origin of an x and y axis.

Break all the vectors into components.

Sum the xcomponents and sum the ycomponents.

Vectorially add the xcomponents and sum the ycomponents.
 Solve problems involving adding or subtracting 2 vector
components.
Formative assessments:

Swimmer problems  Running Bear
(1960, Johnny Preston. The song was #1 for three weeks in January 1960 on the Billboard Hot 100 in the United States. The song also reached #1 in the UK in 1960.)

Airplane problems  Meet me in St. Louis (Judy Garland, 1944 movie)

Displacement problems
Homefun (formative/summative assessment):
Read sections 4.2,
do Practice Problems 5, 7, and 9 on page 125.
Write a paragraph discussing the following question: Before the advent of modern navigation techniques such as GPS, why would having a compass not be enough to successfully navigate the oceans and actually arrive at a given destination?


Essential Question: Is friction helpful or harmful? 
The 3 Models for Friction

Describe static friction.
 Prevents sliding between surfaces
 Variable  adjusts to match the force which would
otherwise cause sliding (the parallel force).
 Correctly use the model for calculating
static friction.
F_{s} = F_{p}
static friction = parallel force
 Correctly use the model for calculating
the transition point between static and dynamic friction.
F_{smax} = m_{s}F_{n}
m_{s}= static COF or static coefficient of friction, an experimentally determined or measured constant for given surfaces

Describe the relationship of normal force to
transition point between static and dynamic friction and describe how this
knowledge is used with fasteners. Fasteners, such as
screws, are a form of inclined plane and have very high mechanical advantages
that can produce extremely high normal forces resulting in extremely high
friction forces that resist "unscrewing".

Describe dynamic or sliding friction.
 Correctly use the model for calculating
the dynamic friction.
F_{d} = m_{d}F_{n}

State which form of friction tends to be lower, the maximum
static friction or sliding friction. Dynamic is generally lower but never higher than the
maximum static friction.

Be aware that there are actually 3 different mathematical models for friction. (see above)

State the relationship between contact area and friction. (Hint: contact area is not in any of the 3 equations)

Calculate friction forces. Note COF = coefficient of friction. Static COF = m_{s}, dynamic COF = m_{d}
 Solve friction problems
Formative assessments:
Jake's dog
Push vs. pull
The Engineering Connection: Friction is a huge issue in many aspects of machine and vehicle design. The drive belts on pulleys cannot slip, but on the other hand, for chutes designed for unloading materials such as coal, the materials must slide easily. Both acceleration in speeding up and slowing down depends on tire friction. Even simple components like nuts and bolts depend on friction to keep from coming undone. Mechanical and materials engineers would be especially concerned with friction.
Homefun (formative/summative assessment): problems 17, 19, 21, page 128

Essential Question: What makes an object slide or roll down a slope? 
Weight Force Components on a Slope

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.
Note: F_{w}= mg
F_{wn} = F_{w} cosβ, this is the component of the weight force that acts perpendicular to the slope.
F_{wp} = F_{w} sinβ, this is the component of the weight force that can make an object slide down a slope.

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

Solve for acceleration of objects on a slope with zero friction.
Formative assessments
An ice road truck sliding down an icy slope
The Engineering Connection: Forces on slopes are a major issue to traffic and civil engineers. If the the slope is two steep in either the upward or downward directions, the result can be serious safety or traffic flow problems.
Homefun (formative/summative assessment): problems 33, 35, 37 page 133

Essential Question:
How can you best prepare for the
test? 
Review of Objectives 1 13 (13 days)
Formative Assessments:

Work review problems at the board

Work practice problems.
Metacognition Problem Solving Question:
Can I still work the problems done in class, several hours
or days later?
Some amount of repetition on the exact same problems is necessary to lock in
learning. It is often better to thoroughly understand a single example of a
problem type than to work example after example understanding none of them
completely.
Relevance: Good test preparation is
essential to performance in physics class.
Homefun (formative/summative assessment): problems 67, 75, 77, 89 (add the vectors mathematically), 85, and 99 , page 141143;
problems turn in on the day stapled to the back of the test.
Summative Assessment: Unit exam objectives 116 
