Lesson Notes By Weeks and Term v5 - Grade 12

Lesson Video

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Performance objectives

• Apply kinematic equations to solve motion problems.
• Explain and apply Newton's Laws of Motion.
• Apply concepts of work, energy, and power.
• Apply the principle of conservation of momentum.
• Solve problems related to vertical projectile motion.

Lesson summary

This week is dedicated to consolidating your understanding of key concepts covered thus far and sharpening your examination techniques. This is a crucial stage, especially as we approach the final examinations. Physical Sciences isn't just about memorizing formulas; it's about understanding the underlying principles that govern the world around us. From understanding electricity that powers our homes to the chemical reactions that occur in our bodies and in the manufacturing industries vital to the South African economy, Physical Sciences provides a framework for understanding and interacting with our environment.

Lesson notes

This week focuses on Mechanics, a cornerstone of Physical Sciences. 2.1 Kinematics Kinematics describes motion without considering the forces that cause it. The key kinematic equations (for constant acceleration) are: `v = u + at` (final velocity = initial velocity + acceleration x time) `s = ut + (1/2)at²` (displacement = initial velocity x time + (1/2) x acceleration x time²) `v² = u² + 2as` (final velocity² = initial velocity² + 2 x acceleration x displacement) `s = ((u+v)/2)t` (displacement = average velocity time)

Where: `v` = final velocity (m/s) `u` = initial velocity (m/s) `a` = acceleration (m/s²) `t` = time (s) `s` = displacement (m)

Projectile Motion: This is a special case of 2D kinematics where the only acceleration is due to gravity (`g = 9.8 m/s²` downwards). Analyze horizontal and vertical components separately. The horizontal velocity remains constant (assuming negligible air resistance), while the vertical motion is subject to gravitational acceleration.