Gravitation — three ways to learn it.

The complete written lesson — Newton's law of universal gravitation & the inverse square, the Cavendish experiment and G vs g, finding g and weighing the Earth, variation of g with altitude, depth & latitude, free fall & weightlessness, orbital velocity, geostationary orbits and PAKSAT — with five worked numericals.

As you scroll, a live panel animates every idea: force arrows shrink by 1/r², Cavendish's fibre twists, a probe rides the g-meter from the Earth's centre to orbit, a lift cable snaps — and the free-fall and Newton's-cannon sections swap in the real 3D experiments you can run yourself.

Drop the ball, time the fall and measure g for yourself on a safe, virtual bench. All of the course's hands-on physics apparatus lives here.