HKDSE Physics Quick Reference: Physical Quantities: Understanding the difference between scalars (magnitude only) and vectors (magnitude and direction). Motion & Acceleration: Calculating speed, velocity, and acceleration ( 𝑎 = Δ 𝑣 / Δ 𝑡 a=Δv/Δt) for moving objects. Kinematics Equations: Applying the four equations of uniformly accelerated motion to solve DSE exam questions. Motion Graphs: Analyzing displacement-time (s-t), velocity-time (v-t), and acceleration-time (a-t) graphs. Free-Falling: Understanding gravity ( 𝑔 = 9.81 𝑚 / 𝑠 2 g=9.81m/s 2 ) and its effect on falling objects without air resistance.