Kinematics lessons for OCR A-level Physics A

In the OCR A-level syllabus

1. Lesson 4Scalars vs Vectors

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

   Syllabus details

   Syllabus: 2.3.1 Scalars and vectors, (a) scalar and vector quantities (learners also give examples of each)

2. 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: 3.1.1 Kinematics, (a) displacement, instantaneous speed, average speed, velocity and acceleration

3. 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: 3.1.1 Kinematics, (a) ... velocity and acceleration; (d) velocity-time graphs; acceleration is gradient; 3.1.2 Linear motion, (a)(i) the equations of motion for constant acceleration in a straight line

Partly in the syllabus

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

1. Lesson 5Distance vs Displacement

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

   Syllabus details

   Syllabus: 3.1.1 Kinematics, (a) displacement, instantaneous speed, average speed, velocity and acceleration; 2.3.1 Scalars and vectors, (a)

   In it: Displacement is listed, and scalar and vector quantities with examples are listed, so the two ideas are covered. Not in it: Distance (path length) is not named as a quantity, so the distance versus displacement comparison is not stated directly.

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: 3.1.1 Kinematics, (a) displacement, instantaneous speed, average speed, velocity and acceleration

   In it: Displacement, average speed and velocity are listed, which are the ingredients for finding an average over a trip. Not in it: Average velocity and trips made of several parts with different speeds are not mentioned.

Not listed as a separate topic

These are basic ideas that the later lessons build on, so they are still worth watching first.

1. Lesson 1Point Mass (Particle) Explained

   Can a walking cat be treated as a particle?

2. Lesson 2Frame of Reference & Coordinate System

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

3. Lesson 3Instant vs Time Interval

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

4. 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?

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

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