The physics
At a planet's surface, gravity depends on the planet's mass M and radius R.
g = G M / R²
Compare with Earth, and G cancels. Work in Earth masses and Earth radii.
g / gₑ = (M/Mₑ) / (R/Rₑ)² with gₑ = 10 m/s²
Write M = ρ × (4/3) π R³. One power of R cancels. So for one kind of rock, g grows in step with R.
g = (4/3) π G ρ R
Mass is the same everywhere. Weight W = m g is not. A spring scale reads weight. A beam balance compares masses.
With the same take-off speed, a jump rises u² / 2g. So the height goes as 1/g.