From: hrock@underg.ucf.org (hardrock)
Newsgroups: alt.rhode_island,tx.news,comp.mail.misc,comp.misc
Subject: physics project dealing with bridges
Date: Thu, 07 Jan 93 17:51:20 CST
Organization: Underground Computing Foundation

     I have a project for school in which I need to construct a
bridge out of toothpicks.  (The requirements are below)  What
information I am looking for, is anything regarding bridges or
actual examples of similar projects.  (Which is allowed)  I need
to have the bridge constructed by January 25, 1993.  Any
information would be very useful.  If you are sending me a
graphics image, the filetypes which I currently can use are: 

     .MAC (MACINTOSH)           .TGA (TRUEVISION TARGA)
     .IMG/.GEM (VENTURA)        .CUT (HALO)
     .PCX (ZSOFT IMAGE FILE)    .BMP (BITMAP)
     .GIF (COMPUSERVE)          .MSP (MS PAINT)
     .TIF (TAG IMAGE FILE)      .LBM (AMIGA)
     .WPG (WORD PERFECT)        .PIC (PC PAINT/PICTOR
     .RLE (COMPUSERVE)          .DRW (DESIGNER)
     .CAD (GRAPHICS WINDOWS CAD).EPS (POSTSCRIPT)
     .WMF (WINDOWS METAFILE)    .GRF (MISCROGRAFX GRAPH)
     RIX                        DELUXE PAINT

If there is not a format listed in which you use can you also end
over either a program to view it or a converter to a format which
I have listed.  The system in which I will be using is a 386 IBM
compatible with 4 mb of ram, 200 mb hard disk, under an
environment of Windows 3.1.


The project
-----------

PURPOSE
     the purpose of this activity is to design and build a bridge
which can be tested for structural strength and then analyzed for
the forced involved.

MATERIAL
     1-2 boxes flat or round toothpicks, white glue, meter stick,
balance, 5 gal bucket, strong cord, 8" piece of 1/4" dowel, water
(or sand), bathroom scale.

PROCEDURE
     1. Research bridge designs from literature or actual
structures.  Take note of bracing points and the reinforcements. 
How is the bridge designed to take into account gravitational,
and load forces and materials?
     2. Design a bridge which will make from toothpicks and white
glue.  The total weight of the finished bridge cannot exceed 40
gm.  You may build and design as long as the roadbed is flat (in
a horizontal plan) and unobstructed to allow a matchbook car to
travel its length.  It must be free standing and allow for a 2 cm
X 30 cm board to pass under the bridge while it rests on a flat
surface.  Allow for adequate drying of the glue.  Draw a sketch
of the bridge to save for further analysis.
     3. To test the bridge's strength, place 2 flat-topped tables
25 cm apart.  Place your bridge between the tables and set the
dowel across the middle of the roadway.  Attach 2 loops of strong
cord on the handle of the 5 gl bucket and place the loops over
the 2 ends of the dowel.  Pour water of sand into the bucket
slowly until the bridge produces and audible crack sound.  Stop
adding weight and weigh the dowel, bucket, and contents on the
scale.  You may continue adding weight until the bridge breaks
completely and then take a second reading.

SUMMING UP
     Study the remains of your bridge and mark on your sketch the
points where the bridge splintered or broke.  Draw arrows to note
the direction of forced acting on the bridge during the testing. 
List ways you could alter the bridge to make it more structurally
sound.  Redraw the sketch of your bridge which includes the
improvements.


Thanks, also I usually do not read this newsgroup, mainly due to
it is a long distance call for me.  E-Mail would be the best.
Thanks
 Hard Rock
--
hrock@underg.ucf.org (hardrock)
Newsgroups: alt.rhode_island