# Is it possible for a person in motion to fall over a ledge?

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1. Jan 7, 2016

### jimmypantspants

The facts are that the person is 183cm, 82kg, meaning his center of gravity is about at 105cm, he was running towards a railing of a balcony that is 108cm high, and allegedly hit the railing then fell over. Is this physically possible?

2. Jan 7, 2016

### Staff: Mentor

Of course. Silly question, IMO.

3. Jan 8, 2016

yes.

4. Jan 8, 2016

### A.T.

You mean "fell over the railing"? Yes, sounds possible. A running human is not a rigid sliding block, and the center of mass moves more than 3cm vertically during running.

5. Jan 8, 2016

### Staff: Mentor

The upper part of the body would rotate around the railing, moving his CoM towards the wrong side and bringing his feet off the floor in a somersault.

6. Jan 8, 2016

### jimmypantspants

Thanks for the reply! Is there any proof I could use in an official debate? A law or theory ...?

7. Jan 8, 2016

### A.T.

In a court of law you would need some recognized expert on forensic bio-mechanics. But in order to demonstrate that it is possible you just could reproduce the situation (not on the balcony).

8. Jan 8, 2016

### jimmypantspants

Ok thank you! Is there any way I could do so without physically recreating it? A physics simulation? A bit of a stretch hahaha but I dont know what else.

9. Jan 8, 2016

### Khashishi

If you run, your center of balance is higher so you have time in the air to complete your stride, unless you are jazz-running or something. Since there are so many open variables here, you probably want to switch your question over from, "is it possible" to "is it likely". As the barrier gets higher, it gets less likely to fall over; but certainly it is still possible if the person sort of leaps over.

10. Jan 8, 2016

### A.T.

If the question is just: "Is it possible?", then an experiment is much simpler, quicker, more reliable and requires much less expertise than a computer simulation.

11. Jan 9, 2016

### CWatters

How did you work out his centre of gravity was at 105cm?

12. Jan 10, 2016

### jimmypantspants

Well approximately that, because i saw that the center of mass of a male is 58% up his body

13. Jan 10, 2016

### jimmypantspants

What are the physics behind falling over a railing? As in someone running into a balcony railing and falling up and over?

Last edited by a moderator: Jan 10, 2016
14. Jan 10, 2016

### Staff: Mentor

It's best to use experimental techniques to answer questions like that...

15. Jan 11, 2016

### A.T.

You have the simple part: classical mechanics. And the complicated part: Complex human anatomy, with muscle contractions triggered in a way that is unpredictable in such a extreme situation. This basically makes any type of modeling of such an event pure guess work.

16. Jan 11, 2016

### CWatters

See post #5 above.

Strange things happen when flexible objects fall over "railings"..