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 course, John can answer too. 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) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe See http://www.seismicnet.com/maillist.html for more information. Try the Wikipedia for a definition: http://en.wikipedia.org/wiki= /Newton Of=20 course, John can answer too.Best Wishes,Jerry Payton----- Original Message -----From:=20 chief.cook.nzSent:Saturday, December 02, = 2006 8:30=20 AMSubject:Re: Zero-length = springHi John

In this formula a NEWTON is what? or = how or=20 why is called a NEWTON the rest

I understand so a

NEWTON:-=20 =3D

Cheers Tamati

From the Castle of Tamati, Hinemoa and = Karauwa the=20 Dog

From the Castle of Tom, Robyn and the Dog

I'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 PM

Subject: 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 for more information.=20 =

__________________________________________________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email = PSN-L-REQUEST@............... =20 with

the body of the message (first line only): unsubscribe

See = http://www.seismicnet.co= m/maillist.html=20 for more information.