## PSN-L Email List Message

Subject: Re: Zero-length spring
From: "Jerry Payton" gpayton880@.......
Date: Sat, 2 Dec 2006 08:50:38 -0600

```Try the Wikipedia for a definition:   http://en.wikipedia.org/wiki/Newton Of

Best Wishes,
Jerry Payton
----- Original Message -----
From: chief.cook.nz
To: psn-l@..............
Sent: Saturday, December 02, 2006 8:30 AM
Subject: Re: Zero-length spring

Hi John
In this formula a NEWTON is what?  or how or why is called a NEWTON the
rest
I understand so a

NEWTON:- =

Cheers Tamati
From the Castle of Tamati, Hinemoa and Karauwa the Dog
From the Castle of Tom, Robyn and the Dog

I'm Just a Stone's Throw Away:- NZ-021-150-33-59 or NZ-07-855-0195
Bush Telegragh:- chief.cook.nz@............
My Regular Pitstop:- Tamati
P.O.BOX
19-356 CENTRAL
HAMILTON
NEW
ZEALAND
----- Original Message -----
From: "John or Jan Lahr"
To:
Sent: Thursday, November 30, 2006 8:20 PM
Subject: Re: Zero-length spring

> At 10:29 PM 11/29/2006, you wrote:
>>Hi John,  I am not too good at math, could you please plug-in some
>>examples/numbers for this formula so I can understand it better? I think
>>its k that I am unclear of.  I understand the rest. Thanks, Ted
>>MgA = kSY/(SA)
>>
>>M = kY/(Ag)
>
> k is the spring constant.  In this example I'm using k = 2 newtons/cm
>
> M is the mass
> Y is the height of the mast
> A is the length of the boom
> g is the acceleration of gravity
>
> The exact numbers don't really matter - the point being that the mass
will
> be stable at any angle of the boom.
>
> There are problems of trying to actually build this device, because
slight
> changes in k with temperature will cause instability.  Even without a
> zero-length spring, one can extend the period by reducing the height of
> the mast.  However, you will soon discover that this will also lead to
> instability if pushed to too long a period.
>
> Cheers,
> John
>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
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Try the Wikipedia for a definition:   http://en.wikipedia.org/wiki=
/Newton Of=20

Best Wishes,
Jerry Payton

----- Original Message -----
From:=20
chief.cook.nz
To: psn-l@..............
Sent: Saturday, December 02, =
2006 8:30=20
AM
Subject: Re: Zero-length =
spring
Hi JohnIn this formula a NEWTON is what?  or =
how or=20
why is called a NEWTON the rest I understand so aNEWTON:-=20
=3DCheers TamatiFrom the Castle of Tamati, Hinemoa and =
Karauwa the=20
DogFrom the Castle of Tom, Robyn and the DogI'm Just a =
Stone's=20
Throw Away:- NZ-021-150-33-59 or=20
=
NZ-07-855-0195         &=
nbsp;           &n=
bsp;       =20
Bush Telegragh:- chief.cook.nz@............=
&nb=
sp;          =20
My Regular Pitstop:-=20
=
Tamati          &nb=
sp;           &nbs=
p;            =
;            =
&=
nbsp;     =20
P.O.BOX 19-356=20
=
CENTRAL          &n=
bsp;           &nb=
sp;           &nbs=
p;            =
;            =
=20
=
HAMILTON          &=
nbsp;           &n=
bsp;           &nb=
sp;           &nbs=
p;            =
;      =20
NEW ZEALAND----- Original Message ----- From: "John or Jan =
Lahr"=20
<JohnJan@........>To: <psn-l@..............>Sent=
:=20
Thursday, November 30, 2006 8:20 PMSubject: Re: Zero-length=20
spring> At 10:29 PM 11/29/2006, you =
wrote:>>Hi=20
John,  I am not too good at math, could you please plug-in some=20
>>examples/numbers for this formula so I can understand it =
better? I=20
think >>its k that I am unclear of.  I understand the =
rest.=20
Thanks, Ted>>MgA =3D kSY/(SA)>>>>M =3D=20
kY/(Ag)>> k is the spring constant.  In this =
example I'm=20
using k =3D 2 newtons/cm>> M is the mass> Y is =
the height=20
of the mast> A is the length of the boom> g is the =
acceleration=20
of gravity>> The exact numbers don't really matter - the =
point=20
being that the mass will > be stable at any angle of the=20
boom.>> There are problems of trying to actually build =
this=20
device, because slight > changes in k with temperature will =
cause=20
instability.  Even without a > zero-length spring, one can =
extend=20
the period by reducing the height of> the mast.  However, =
you will=20
soon discover that this will also lead to > instability if =
pushed to=20
too long a period.>> Cheers,>=20
John>>>>=20
=
__________________________________________________________>>=
;=20
Public Seismic Network Mailing List (PSN-L)>> To leave =
this list=20
email PSN-L-REQUEST@...............
=20
with the body of the > message (first line only): =
unsubscribe>=20
See http://www.seismicnet.co=
m/maillist.html=20