Mr. Rogers' Honors Physics Syllabus 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Fundamentals(1) 1D Motion(2) Accel Motion(3) 1D Force(4)

Forces in 2 Dimensions-- Chapter 5
 SC Standards : Indicators P-2.1 Represent vector quantities (including displacement, velocity, acceleration, and force) and use vector addition. P-2.7 Use a free-body diagram to determine the net force and component forces acting upon an object

 Practice Test Study Guide
 Objectives
 Essential Question: Does 1 + 1 = 2?

1. State the relationship between a force's direction to the resulting acceleration's direction. They are always the same.

2. State the relationship of a velocity's direction to the resulting displacement's direction. They are always the same.

3. Sketch 2 ways to graphically add vectors. vectors are represented as arrows. The length of the arrow reprsents the magnitude and the way the arrow points represents the direction. For addition purposes, arrows can be moved around as long as the angle they make with respect to the verticle and horizontal dimentions is not changed.

• head-to-tail or heal to toe
• parallelogram
1. Define vector components. A vector's components are the x and y coordinates of a vector, assuming that the vector's tail is at the origen. Components can also be considered the or x and y parts of a vector that added together will equal the original vector.

2. Given vector components find the resultant vector (A) and its angle (theta).
3. A = (Ax^2 + Ay^2)^0.5

(theta) = arctan Ay/Ax

4. Given a vector (A) find its components Ax and Ay.

Ax = A cos (theta)

Ay = A sin (theta)

Homefun (formative/summative assessment): Read sections 5.1

 Formative Assessment: Physics Investigation Title Research Question Background Hypothesis Data, Calculations Conclusions Follow up Questions Deliverables Resources/Materials

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

1. State the relationship between the magnitudes of vector components. They are totally independent of each other.
2. State the relationship between the direction of vector components. They are at a 90 degree angle with each other.
3. Add vectors together using the component method (see Problem Solving Strategies, p. 123).
4. Solve problems involving adding or subtracting 2  vector components.
• Swimmer problems--Running Bear
• Airplane problems
• Displacement problems

Homefun (formative/summative assessment): Read sections 4.2, do Practice Problems 5, 7, and 9 on page 125.

 Essential Question: Is friction helpfule or harmful?

The 3 Models for Friction

1. Describe static friction.

• Prevents sliding between surfaces
• Variable - adjusts to match the force which would otherwise cause sliding (the parallel force).

2. Correctly use the model for calculating static friction.

Fs = Fp

static friction = parallel force

1. Correctly use the model for calculating the transition point between static and dynamic friction.

Fsmax = msFn

1. 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".

2. Describe dynamic or sliding  friction.

• Resists sliding between surfaces
• Constant for a given normal force
3. Correctly use the model for calculating the dynamic friction.

Fd = mdFn

1. 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.

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

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

4. Calculate friction forces.
5. Solve friction problems

Jake's dog

Push vs. pull

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

1. Find the normal (Fwn) and parallel (Fwp) components of the weight force (Fw) for objects on a slope that makes an angle of with the horizon β.

Fwn = Fw cosβ

Fwp = Fw sinβ

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

2. Solve for acceleration of objects on a slope (zero friction).

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 (1-3 days)

Formative Assessments:

1. Work review problems at the board

2. 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 141-143; problems turn in on the day stapled to the back of the test.

Summative Assessment: Unit exam objectives 1-16