HKDSE Physics Core Notes - Quick Summary: Chapter 4: Work, Energy and Power: Comprehensive revision notes for HKDSE Physics by Billy Sir. Work Done: Learn how work is calculated ( 𝑊 = 𝐹 𝑠 cos ⁡ 𝜃 W=Fscosθ) and the difference between positive work (gaining energy) and negative work (losing energy due to friction). Mechanical Energy: Understand the formulas and definitions for Kinetic Energy ( 𝐾 𝐸 = 1 2 𝑚 𝑣 2 KE= 2 1 ​ mv 2 ), Gravitational Potential Energy ( 𝐺 𝑃 𝐸 = 𝑚 𝑔 ℎ GPE=mgh), and Elastic Potential Energy. Conservation of Mechanical Energy: Discover how energy transforms in an isolated system, featuring a detailed breakdown of a simple pendulum swinging from its highest point (max GPE) to its lowest point (max KE). Mechanical Power: Master the rate of energy transfer and work done, including the power formula for objects moving at a constant velocity ( 𝑃 = 𝐹 𝑣 P=Fv). Looking for more HKDSE Physics and Chemistry notes? Contact Billy Sir for past paper analysis and exam techniques.