Experiments you can run yourself.
Newton's law of universal gravitation: why the gravitational force decreases with the square of the distance. Interactive simulation, the formula F = Gm₁m₂/r² and a satellite's orbit.
Surface gravitational acceleration g=GM/R² depends on the mass and radius of a celestial body. An astronaut's mass is constant, but their weight F=mg changes from planet to planet.
Newton's thought experiment: a cannonball fired horizontally at high speed does not fall but orbits the Earth. For v=v_I the trajectory is a circle; for v≥v_II — escape.
Field strength decreases with the square of the distance: g=GM/r².
A lift accelerates and the scale changes its reading. When weight disappears.