17 ms·

How is a collision not just another acceleration?

• amluto 6y ago
  In a collision, the helmet gets hit and, subject to some degree of padding and such, transfers the impact to the head. If you’re sitting in a sled and the sled accelerated rapidly, your head and your helmet must accelerate with it, although you may not perfectly track its path. Unless the helmet is also secured to your torso, all the forces on the helmet come from your head. You would need tremendous acceleration of your head to meaningfully deform any but the softest padding.