Lesson Notes By Weeks and Term v5 - Grade 12

Lesson Video

This page supports the lesson note with a companion video and a short classroom-ready summary.

For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.

Performance objectives

• Identify and address weak areas in your knowledge.
• Apply physics and chemistry principles to solve complex problems.
• Effectively manage time during examinations.
• Interpret and analyse graphical data.
• Use scientific vocabulary and definitions accurately.

Lesson summary

This week is dedicated to intense revision and examination preparation. Physical Sciences requires a deep understanding of concepts and the ability to apply them to solve problems. This week is not about learning new material, but solidifying what you already know. We'll focus on identifying knowledge gaps, strengthening problem-solving skills, and building confidence for the upcoming examinations. This is particularly important in the South African context because success in Physical Sciences opens doors to various career paths crucial for national development, such as engineering, medicine, and technology.

Lesson notes

This week's revision should cover all topics studied throughout the year.

However, we'll focus on common areas of difficulty and high-weightage topics in examinations. I will provide an overview and some examples for mechanics, electrostatics, chemical equilibrium, acids and bases, and organic chemistry. Mechanics (Newton's Laws and Vertical Projectile Motion): Newton's Laws of Motion: Newton's First Law (Law of Inertia): An object remains in a state of rest or uniform motion unless acted upon by a net external force. In a South African context, consider a taxi driving at a constant speed until the driver suddenly brakes. Passengers without seatbelts experience inertia and continue moving forward.

Newton's Second Law: The net force acting on an object is directly proportional to the rate of change of momentum of the object and is in the same direction as the change in momentum. Mathematically, F_net = ma. The acceleration is directly proportional to the force and inversely proportional to the mass. Think about pushing a grocery trolley at a supermarket. The heavier the trolley (greater mass), the harder you need to push (greater force) to achieve the same acceleration.

Newton's Third Law: When one object exerts a force on another object, the second object exerts an equal and opposite force on the first object. When you walk, you push the Earth backward, and the Earth pushes you forward with an equal force.

Vertical Projectile Motion: The motion of an object projected vertically upwards or downwards, subject only to the force of gravity.

Key concepts include: Acceleration due to gravity (g): Approximately 9.8 m/s² downwards on Earth.

Equations of motion: v_f = v_i + at Δx = v_it + 1/2at² v_f² = v_i² + 2a*Δx Δx = ((v_i + v_f)/2)t Important points: At the highest point, the velocity is zero (v_f = 0). The time taken to go up is equal to the time taken to come down if the initial and final heights are the same.