Topic
Physics
8 articles on physics: the maths or physics explained, ready-to-teach lesson plans, and how to build each slide in Tracé.
Why 45° Is the Best Launch Angle (and When It Isn’t)The proof that 45° gives the longest throw, why 30° and 60° land in the same place, and why real throws use less: launch height and air resistance.
The Brachistochrone: Why the Fastest Path Is a CurveWhy a ball on a cycloid beats one on a straight ramp (3.17 s against 3.76 s for a 20 m drop), the 1696 challenge behind it, and how to animate the race.
Free-Body Diagrams and Newton’s Second Law: A Lesson PlanHow to teach free-body diagrams step by step, a worked example (30 N push, 10 N friction, 5 kg: a = 4 m/s²), the classic mistakes and check questions.
Adding Vectors Head to Tail: A Lesson PlanTeach vector addition: head-to-tail drawings, adding components, the magnitude with Pythagoras, a river-crossing example, common mistakes and checks.
The Simple Pendulum Period: T = 2π√(L/g) Lesson PlanTeach the simple pendulum period formula T = 2π√(L/g): what changes the period and what does not, the small-angle limit, worked examples and checks.
Wave Speed, Frequency and Wavelength: v = fλ LessonTeach the wave equation v = fλ: wavelength, frequency, period and amplitude on one animated wave, examples with sound and light, mistakes and checks.
Circular Orbits and Gravity: Why Satellites Don’t FallA lesson on circular orbits: gravity as the centripetal force, orbital speed v = √(GM/r), the ISS at 7.7 km/s and 92 minutes, geostationary orbit, and mistakes.
Ohm’s Law and Simple Circuits: A Lesson PlanTeach Ohm’s law V = IR with a live circuit: current, voltage, resistance, series and parallel resistors, power, the classic misconceptions and checks.