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by maccard 4020 days ago
> s soon as it breaks, it can't absorb much energy anymore, thus it impacts your head a lot more.

But it has still absorbed the energy that it took to crack the helmet. If the strength of the impact is exactly the same as the strength of the helmet, then the helmet will simply crack, and leave your skull intact. However if you're not wearing the helmet, your head receives the full force of the impact.