1What makes a thing sink in
Two things matter: the push, and the footprint
You only need two ideas. Watch each one:
The push (the weight)
How hard the thing presses down. A heavy thing pushes hard on the ground. A light thing barely presses at all.
The footprint
How much ground it actually touches. A wide flat foot touches a lot of ground. A skinny edge touches almost none.
2Two tires, one weight
The skinny tire vs the wide tire
Imagine both tires carry the exact same weight. The only thing that's different is how wide they are where they meet the ground:
Tiny footprint
All the weight is crammed onto a thin little strip of ground.
Big footprint
The same weight is shared across a wide, flat strip of ground.
3Your turn — load it up
Pile weight on a block and watch it sink
Here's a block sitting on soft sand. Make it heavier or lighter and watch how far it sinks. Get a feel for it first — this is the part everybody already guesses.
4Now the real test
Same weight every time — only the footprint changes 👣
This time the weight is locked. It never changes. The only thing you can move is how wide the foot is. Guess first — then drag the footprint and watch.
Guess before you drag it
Here's the catch: the weight is locked identical — the wide foot is not carrying any less. So if nothing gets lighter, can just spreading that exact same weight wider really keep it on top — or does the same weight have to sink the same no matter how it's spread?