# Funny question

This isn't a homework question, just a random question. The other day I hit my head really hard on the ground and ended up getting a concussion. The athletic trainer at my school said that if I would have hit my head on a pad, I would not have received a concussion. Why is this?

Besides the obvious answer that the pad is softer. I mean, does the pad make that much of a difference?

fluidistic
Gold Member
Yes it does.
When you hit something soft, your exposed part of your body decelerates at a lower rate than if you hit a solid ground. The difference is that the brain doesn't get an acceleration as big as if you hit a solid ground. A greater acceleration of the brain makes it hits the skull faster (so stronger) so it really makes a difference.

The time allowed for acclerating is longer if the pad is hit than if something with a high elasticity is hit, then the force would be less because force is change in momentum relative to change in time.
Are you all right?

Last edited:
PhanthomJay
Homework Helper
Gold Member
Per Newton's 2nd law, Impulse = Change in Momentum, that is $$F\Delta t = m\Delta v)$$, which is to say, the force on your head, F is $$F = m\Delta v/\Delta t$$. So since you would hit the pad or ground at the same speed, it's the time, t, that lessens the force on your head using the soft pad, because it takes a longer time and a longer distance for your head to come to a stop.

Wow, I didn't know a small pad would make that big of difference. Thanks!

Yeah, I'm okay. I actually got lucky, I didn't get that bad of a concussion. Lol.

gmax137