# Force of impact for human falling different heights

1. May 9, 2016

### brettsyoung

1. The problem statement, all variables and given/known data
I am trying to prove a human head hitting the ground after falling backwards down a hill suffers a significantly greater impact than one hitting the ground on a flat surface. The person is 95KG, 180cm tall, and the impact point of the head was 60cm below (in altitude) the point where the feet were placed at the time of falling.

2. Relevant equations

3. The attempt at a solution
Unfortunately I have no physics background and have no idea where to start. This is one element of a broader forensic brief I would like to put together regarding a theoretical random assault in a sport's stadium. At some stage I understand I will need a professional report on this element of the brief, but first I would be very grateful for a ballpark assessment on whether this is indeed a relevant issue, and whether forces and hence injury are significantly greater as the slope comes into play. In other words, does pushing hooligans down the stands risk greater physical threat then pushing them up. Inituitively it does, but infact I'm less sure My schoolboy physics doesn't go beyond its ability to confuse me, so apologies if this seems a dumb question. Rather I hope it intrigues some of you. Thanks Brett

2. May 9, 2016

### Bystander

Ask yourself, "How far are they falling?"

3. May 9, 2016

4. May 9, 2016

### haruspex

I think you mean 2.4m and 1.8m.
But is the velocity (i.e. momentum) the key measure or is it v2 (energy)?

5. May 9, 2016

### brettsyoung

Thanks for your replies. Very useful! Velocity is a suitable measure as we have lots of data of the effect of impact at increasing rates of velocity on the human head, including key low velocity ranges where the relative effect increases at a greater rate than the velocity. Thanks again. I didn't expect to hear back so quickly! regards Brett

6. May 10, 2016

### DrSteve

You're correct - I meant 1.8 m and 2.4 m