2D Motion
Physics of Geosynchronous Satellites
A satellite hangs over the same patch of Earth for years without ever firing an engine. Students unpack the circular-motion balancing act — gravity pulling in, orbital speed pushing out — that keeps it locked in place, and why that "golden altitude" is the same for every geostationary craft.
Open Reading Passage
2D Motion
Newton's Cannonball: The Thought Experiment That Explained Orbits
Fire a cannonball fast enough from a tall enough mountain, and it never lands — it just keeps falling as the Earth curves away beneath it. Students use Newton's own thought experiment to see how an orbit is really projectile motion in disguise, with horizontal velocity and vertical gravity acting completely independently.
Open Reading Passage