Mr. Rogers' IB/AP Physics I: Mechanics Objectives Syllabus 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Kinematics (1) Vector Addition (2) Projectile Motion (3) Newton's Laws (4)

Chapter 5: The Laws of Motion

AP Physics C Newtonian Mechanics: B. Newton's laws of motion Approx 10%, cumulative 34%
1.Static equilibrium (first law)
2.Dynamics of a single particle (second law)
3.Systems of two or more bodies (third law)

 Practice Test Study Guide
 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). F = net Force 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: Read 5.1 to 5.5
 Activities Lesson 1 Pre-assessment: 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, Acceleration, and Elevator Problems

1. Draw free body diagrams.

• Generally shows the object as a square
• Show only forces from the outside acting on the object.
1. State 3 ways "g" can be defined.

• Acceleration of a free falling body
• A unit of acceleration (freefall only)
• A gravity constant used for calculating weight force.
1. Explain which force causes the sensation of weight.

2. Solve elevator problems (both vertical and horizontal).

• "g" is a gravity field strength vector not an acceleration.
• "g" is negative because it points downward.
1. Solve elevator problems.
2. Solve 2 cable elevator problems.

Homefun: Read 5.6, prob. 1, 3, 29, 33, 51 p. 141-145 Serway

 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? 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

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

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

3. 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: Read 5.6, prob. 24,  31, 45 p. 141-143 Serway

 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
 Mini-Lab 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

1. Find the normal and parallel components of the weight force for objects on a slope.

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

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

Homefun: 22, 69 p. 141-143 Serway

 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)

1. State the force conditions required for static equilibrium.

SFx = 0, SFy = 0, SFz = 0

1. Solve static equilibrium, cable problems. (buzzard problem)

2. Solve static slope problems.

Homefun: prob. 21, 27, 35 p. 141-143 Serway

 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