system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: when two objects colide what decides which breaks?

Like if I threw an egg at a wall the egg would break, but if the egg is going really fast the wall would break too? Whats the underlying mechanic for this?
gpt
The amount of force involved. The egg needs 1kN of force applied to the shell to break and the wall needs 100kN. Force from the impact is proportional to the speed you throw at and the mass of the thrown object.

Edit: after the egg shatters the force it exerts on the wall quickly drops because it isn't a single solid object anymore, so the calculations get a bit harder than just speed and mass. But that's the general idea.

(All the values just estimated without any calculations, actual numbers are probably very different).