Physics lessons where students get their hands on the physics: drag, pick scenarios, pause and check the numbers. Each lesson is a single page that opens on a phone or a computer, with nothing to install.
Frames of reference, average velocity, uniform and accelerated motion, meeting points, free fall, projectiles and vectors.
Forces as vectors, Newton's three laws, weight and normal force, friction, inclined planes, systems of blocks, mechanical energy, impulse and collisions.
Period and frequency, radians, centripetal acceleration and force, pulleys, sine and cosine, accelerated circular motion, the globe of death and Kepler's laws.
Newton's law, gravitational fields on other worlds, orbits and Newton's cannon, weightlessness, Kepler to weigh planets, escape velocity and tides.
Equilibrium of a point, moments, seesaws, levers, centre of mass and toppling, supported beams and pulleys.
Density, pressure, Stevin's law, atmospheric pressure and Torricelli, communicating vessels, the hydraulic press and buoyancy.
Temperature and the Maxwell curve, scales, Joule's experiment, thermal expansion, specific heat, phase changes, calorimetry, heat transfer and gases.
Work done by a gas, internal energy, the first law, the four processes, cycles and engines, the second law and Carnot, fridges and air conditioning.
Shadows and the pinhole camera, plane and curved mirrors, refraction, total internal reflection, lenses, the human eye and colour.
Springs and pendulums, what a wave is, reflection and refraction, interference, standing waves on a guitar, sound and the Doppler effect.
Electric charge, charging by friction, contact and induction, Coulomb's law, fields and field lines, potential, uniform fields between plates, lightning conductors and capacitors.
Magnets and compasses, currents that create fields, magnetic forces on charges and wires, electric motors, induction, generators and transformers.
Current, potential difference, Ohm's laws, power and the electricity bill, bulbs in series and in parallel, circuits with meters and real cells.
Resistors and Kirchhoff, AC and DC, RC and RLC circuits, diodes and Zeners, bipolar transistors and MOSFETs, power supplies, op-amps and the 555, with a multimeter and an oscilloscope on every bench.
Photons and the spectrum, the photoelectric effect, the Bohr model, the double slit, radioactivity and half-life, nuclear energy and relativity.
Every step has a drawing that responds to the controls. The numbers on screen use the same formulas as the text.
Questions that ask you to try things: "double the mass", "cut the string", "pause and check".
10 per step (4 basic, 4 intermediate and 2 challenge), with the solution hidden until you click.
At the end, challenges that mix the steps, five ENEM-style questions (ENEM is Brazil's national secondary-school exam) with pointers to real past papers, and a box with every formula in the lesson.