Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Harry01 on 15/08/2023 06:29:22

Title: Calculating the force of a falling object on concrete
Post by: Harry01 on 15/08/2023 06:29:22

Bit obsessive but I was wondering how you would work out the force generated from someone falling from a height of say 100metres with a weight of 100kg onto concrete. I was using E=mgh. Energy is equal to mass times gravitational field strength times the height. How do I convert that into a force in Newtons?

Title: Re: Calculating the force of a falling object on concrete
Post by: Bored chemist on 15/08/2023 08:33:12

Quote from: Harry01 on 15/08/2023 06:29:22

How do I convert that into a force in Newtons?

You divide it by a distance.

(Average) Force = weight times distance fallen divided by stopping distance.

Title: Re: Calculating the force of a falling object on concrete
Post by: alancalverd on 15/08/2023 10:10:26

And you need to take into account Young's modulus of the human body and the speed of sound in soft tissue. It's more of a squish than a bang. I think you can ignore the compressibility of concrete for a first-order approximation.

Sadly,  the Transport and Road Research Laboratory, the Motor Industry Research Association and the Institute of Aviation Medicine have plenty of models and real life data.

You won't reach terminal speed from 100m but you do need to correct for drag. E _impact< mgh, depending on clothing and posture.

Title: Re: Calculating the force of a falling object on concrete
Post by: Petrochemicals on 15/08/2023 16:03:43

F= ma

https://en.m.wikipedia.org/wiki/Newton_(unit)

Title: Re: Calculating the force of a falling object on concrete
Post by: Zer0 on 20/08/2023 20:45:41

@Harry01

Welcome Back!