Motion in 2D — Physics from Scratch | PHYS 101 Lecture 3

Why does a thrown ball trace a parabola? Why is 45° the perfect launch angle? And how can something accelerate while moving at constant speed? This is Lecture 3 of QN's General Physics I series — motion in two dimensions, built from the ground up. No memorising formulas. Every result is derived from one simple idea: each direction is independent. ⏱ Chapters: 0:00 Newton's cannon 1:49 Why a vector has parts 3:29 Independence of x and y 5:03 Projectile motion from scratch 8:45 Why 45° is optimal 10:10 Dropped vs fired ball 11:50 Circular motion 14:22 The swimmer and the river 16:09 Two traps and the cliff problem 18:00 Summary Part of the QN university series — every major STEM subject taught the way top universities teach it. #Physics #ProjectileMotion #Kinematics #PHYS101 #CircularMotion #Vectors #RelativeVelocity #GeneralPhysics #UniversityPhysics #LearnPhysics #Education #QN