Kinematics lessons for AP Physics 1

In the AP 1 syllabus

1. Lesson 1Point Mass (Particle) Explained

   Can a walking cat be treated as a particle?

   Syllabus details

   Syllabus: Unit 1, Topic 1.2 Displacement, Velocity, and Acceleration, 1.2.A.1 (object model: an object may be treated as a single point)

2. Lesson 2Frame of Reference & Coordinate System

   Sitting still on a speeding subway: are you moving or not?

   Syllabus details

   Syllabus: Unit 1, Topic 1.4 Reference Frames and Relative Motion, 1.4.A.1; Unit 1, Topic 1.1 Scalars and Vectors in One Dimension, 1.1.B.1 (signs in a one-dimensional coordinate system)

3. Lesson 4Scalars vs Vectors

   Current has a direction, so why is it a scalar?

   Syllabus details

   Syllabus: Unit 1, Topic 1.1 Scalars and Vectors in One Dimension, 1.1.A.1 to 1.1.A.3

4. Lesson 5Distance vs Displacement

   Run a full lap on a 400 m track: is your displacement 400 m or 0?

   Syllabus details

   Syllabus: Unit 1, Topic 1.1 Scalars and Vectors in One Dimension, 1.1.A.3 (distance is scalar; position, displacement are vectors); Unit 1, Topic 1.2, 1.2.A.2 (displacement is the change in position)

5. Lesson 6Average Speed vs Average Velocity vs Instantaneous Velocity

   Two taxi rides to the same place: 7.5 km in 14 min, or 10 km in 15 min. Which one is faster?

   Syllabus details

   Syllabus: Unit 1, Topic 1.2, 1.2.B.2 (average velocity); Unit 1, Topic 1.3 Representing Motion, 1.3.A.4.i (instantaneous velocity); Unit 1, Topic 1.1, 1.1.A.3 (speed is a scalar)

6. Lesson 9What Is Acceleration? Why It's 180, Not 20

   You gain 30 points in 120 days, your friend gains 10 points in 10 days. Who improved faster?

   Syllabus details

   Syllabus: Unit 1, Topic 1.2, 1.2.B.3 and 1.2.B.4 (accelerating if speed and/or direction changes); Unit 1, Topic 1.3, 1.3.A.4.ii

Partly in the syllabus

Only part of the lesson is in the syllabus. Each lesson says which part.

1. Lesson 3Instant vs Time Interval

   Is "the 3rd second" a moment or a stretch of time?

   Syllabus details

   Syllabus: Unit 1, Topic 1.2 Displacement, Velocity, and Acceleration, 1.2.B.1 and 1.2.B.5 (interval of time; very small interval); Unit 1, Topic 1.3 Representing Motion, 1.3.A.4.iii

   In it: Intervals of time are used in the definitions of average velocity and acceleration. Not in it: There is no entry that defines an instant versus a time interval or the 'nth second' idea.

2. Lesson 7How to Find Average Velocity of a Multi-Part Trip

   A car covers 1/4 of the trip at 20 m/s and the rest at speed v. The whole-trip average velocity is 16 m/s. What is v?

   Syllabus details

   Syllabus: Unit 1, Topic 1.2, 1.2.B.1: 'Averages of velocity and acceleration are calculated considering the initial and final states of an object over an interval of time.'; 1.2.B.2: 'Average velocity is the displacement of an object divided by the interval of time in which that displacement occurs.'

   In it: Average velocity is defined as displacement divided by the time interval, using initial and final states, which is the whole-trip method. Not in it: Average speed, trips split into stages, and finding one stage's speed from the whole-trip average are not named.

3. Lesson 8How to Find Change in Velocity: Why It's 7, Not 3

   A ball hits the ground at 5 m/s and bounces up at 2 m/s. Is its change in velocity 3 m/s or 7 m/s?

   Syllabus details

   Syllabus: Unit 1, Topic 1.2, 1.2.B.3 (average acceleration = change in velocity / interval of time); Unit 1, Topic 1.1, 1.1.A.3.ii (in one dimension the sign gives the direction); Unit 1, Topic 1.3, 1.3.A.4.iv

   In it: Change in velocity is used inside average acceleration, and signs show direction in one dimension. Not in it: Finding Δv for a bounce, as a standalone skill, has no learning objective.

4. Lesson 10Speeding Up or Slowing Down? Check a and v

   A car's acceleration keeps getting smaller. Is it speeding up or slowing down?

   Syllabus details

   Syllabus: Unit 1, Topic 1.2, 1.2.B.4 (accelerating if the magnitude and/or direction of velocity changes); Unit 1, Topic 1.3 Representing Motion, 1.3.A

   In it: An object accelerates when its speed or direction changes, and motion is described using graphs and diagrams. Not in it: There is no stated rule that a and v in the same or opposite directions mean speeding up or slowing down.