Ken,
It's not the 1g acceleration of a falling object that kills, it's the rate
of DEcelleration when said object hits terra firma that's the nuisance.
Acceleration is rate of change of velocity, so in going from very fast to
dead stop is next to no time, your decelleration (negative acceleration) is
going to be very high. When factored against normal 1g acceleration, the
figure you get is the number of g's acceleration you flight recorder has to
withstand.
Say an object hits the ground at 500 mph. That's 223.5m/s. Lets say it
takes 35 milliseconds to reach a dead stop from that speed: 223.5/0.035 = a
negative acceleration of 6386 m/s/s. Divide this by 9.8 (normal
acceleration due to gravity) and you have the number of g's (approx 650 in
this case).
Still need your physics book?
Peter Duncan
Peter Duncan
Ken Patel
<[log in to unmask] To: [log in to unmask]
OM> cc: (bcc: DUNCAN Peter/Asst Prin Engr/ST
Sent by: Aero/ST Group)
TechNet Subject: Re: [TN] Question for the physics
<[log in to unmask] "gurus"
ORG>
10/11/01
06:28 AM
Please
respond to
"TechNet
E-Mail
Forum."
All,
If G force is the gravitation force acting on the object then why many
times an object is
being designed to take so may G forces. What I have heard that voice
recorder of the plane
that went down in Pennsylvania can take on 700G force! So, if the free fall
is 1 G then why
design 700 times safer. So, height above the ground does matter. May be I
got to take a look
at the physic's book unless someone explain in layman's term.
re,
Ken Patel
Timothy Reeves wrote:
> No Jason,
> I am not a guru, but that's OK. They are not interconvertible. One is a
> measure of force, the other acceleration (actually a dimensionless
> multiplier of the standard gravitational acceleration, g, 9.8 m/s^2). If
you
> have an object in mind of a known mass, you could find the force exerted
on
> it given the acceleration ("G's") by F = m a.
>
> Example: 100 gram object subjected to 5 G's ---------> F = 0.1 kg * 5 *
9.8
> m/s^2 = 4.9 Newtons or 0.5 kilogram force or 1.1 lb-force.
>
> Tim Reeves
>
> -----Original Message-----
> From: Jason Gregory [mailto:[log in to unmask]]
> Sent: Tuesday, October 09, 2001 9:01 AM
> Subject: Question for the physics "gurus"
>
> How do you convert pound/kilogram to G-force? Is this convertable? Since
> G-force is somewhat time derived and pound/kilogram is force derived?
> Any help is appreciated.
>
> Jason Gregory
> Software Specialist - NPI Group
> SCI Systems/Plant 2
> 13000 S. Memorial Pkwy.
> Huntsville, AL. 35803
> (256) 882-4107 x3728
> [log in to unmask]
>
>
---------------------------------------------------------------------------------
> Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
> To unsubscribe, send a message to [log in to unmask] with following text in
> the BODY (NOT the subject field): SIGNOFF Technet
> To temporarily halt delivery of Technet send the following message: SET
Technet NOMAIL
> Search previous postings at: www.ipc.org > On-Line Resources & Databases
> E-mail Archives
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
> information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
>
---------------------------------------------------------------------------------
---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send the following message: SET
Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
---------------------------------------------------------------------------------
[This e-mail is confidential and may also be privileged. If you are not the
intended recipient, please delete it and notify us immediately; you should
not copy or use it for any purpose, nor disclose its contents to any other
person. Thank you.]
---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------
|
