KN is this acurate?

[Tony Croft aka hamadryad]

Hi all, probably had this conversation many times in here but just need some confirmation from you bods that the information below is correct?

 

Kilonewton (kN) is a measure of force= force of 1 kN of gravity would be exerted on something that weighs approximately 224.8 pounds (lbs).

 

1kN = 224.8 lbs

 

I would also like to know how one calculates Velocity+Static wieght= KN force load

 

and finaly is there some symbols for velocity, Static wieght and force?

 

Thanks

[Lancstree]

1 KN = 224.8 Pound force

 

Can't really help with the second part of your question.

Have you downloaded Uconeer? Its a handy little conversion tool that someone posted on here some time ago.

[Tony Croft aka hamadryad]

No I havent but I did find the scientific equation symbols for it at wiki answers.

[Tony Croft aka hamadryad]

Im just curios to work out the wieght of a twelve stone human falling for three secons which equates to 30% of terminal velocity and also from that work out the max KN force from a fall

[Justme]

3 seconds sounds like a long fall.

 

How far would you have fell?

[Tony Croft aka hamadryad]

3 seconds sounds like a long fall.

 

How far would you have fell?

 

I reckon 3 seconds fall has to be about 80ft or maybe a little more, thinking about a log dropping from a 100fter:001_huh:

[WeeDee]

Hama, if it's of any use I've calculated some close figures to your imperial measurements.

 

A 90kg mass falling 25m (approximate to your suggestion) with almost no travel after initial impact (the rope catching the falling mass) will exert a force of 315000 N on the system.

 

So that's a force of 315 kN.

[Tony Croft aka hamadryad]

Hama, if it's of any use I've calculated some close figures to your imperial measurements.

 

A 90kg mass falling 25m (approximate to your suggestion) with almost no travel after initial impact (the rope catching the falling mass) will exert a force of 315000 N on the system.

 

So that's a force of 315 kN.

 

best keep the slack out of our ropes eah! thanks for that!

 

[WeeDee]

Remember - that calculation assumes almost no stretch in the rope.

 

To give a more useful result we could assume a stretch of 1m, thus giving a final force of just over 22 kN.

[detritus21]

What you may be wanting are a combination of speed distance calculations and force calculations. I did A level physics and maths back in the day and vaguely remember working out stuff like above.

 

v=u+at where v = final velocity u = initial velocity + acelleration x time

 

v= 9.81x3

 

final velocity is 29.43 metres per second

 

s=0.5xat2

therefore the distance fallen is 0.5*9.81*9 = 44m approx 150feet

 

I may come back and calculate the force later. But my brain hurts.

Edited April 5, 2010 by detritus21
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