Physical Research Bridge Project

Build Requirements:

-The Bridge must span an 8 inch gap.

-The Bridge must be able to support a 2” X 2” “load block” of wood from which the load will be suspended.

-The bridge must allow for the passage of a rod vertically from the “load block” to below the bridge.

-The Bridge must have NO members made up of more than 2 pieces of wood joined in parallel (laminated) unless you are constructing a suspension bridge.

Ex.

Bridge Materials:

-12-16 feet (192 inches) of 1/16” X 1/8” Balsa wood

-Elmers Glue

Tools:

-Cardboard building base

-Wax paper

-Scissors

-Ruler, Protractor

-Pencil

Your Tasks:

-Draw some sketches of the type of Bridge you want to build.

Pencil Line Drawing

-Draw a full size pencil line plan side view, top view, bottom view, and end view, with member lengths clearly labeled.

-Add up all member lengths to make sure it falls within the 168 inches of Balsa wood supplied.

Ex.

-Draw a full size “full widths” side view, top view, bottom view, and end view, showing member thickness along with shading (coloring) of 1st layer, 2nd layer, etc. Level 1 is in contact wit the cardboard building base, level 2 is on top of that, etc.

Ex.

-Tape your full size Bridge side view plan on top of your cardboard building surface. Place a layer of wax paper on top of your plan and tape it to the cardboard. This will be the outline you follow in constructing your Bridge. Be neat and detail oriented when constructing your Bridge!

-Test Bridge to destruction.

-Write Bridge Report

Report Requirements:

Your Bridge must have a name

Write up:

-Summary of why your chose your design

-Describe construction details, patches, extra bits of wood added for leveling, corner braces, etc.

-The good aspects of your design

-The bad aspects of your design

-How your design could be improved

Plan Drawing:

-Your Bridge must include a side, top, and end view drawing with layering levels and overall length, width and height labeled on your drawing.

*Your top view must show what you would see of the bottom layer when looking down from the top. OR you could do a separate top view showing just what is on top and a separate bottom view (looking up from underneath the bridge) to show what is on the bottom.

Sample Bridge Design 1

Sample Bridge Design 2

Sample Side View Drawing

Sample Top and Bottom View Drawing

Sample End View Drawing

Design Analysis:

*Include this sheet in your report. Fill in the blanks below and show your calculation for efficiency using the formulas below

English Metric

Bridge Height: _____________ in. _______________ cm.

Bridge Width: _____________ in. _______________ cm.

Bridge Length: _____________ in. ________________ cm.

Mass of Bridge: _____________ oz. ________________ g.

Load supported: _____________ oz. ________________ g.

______________ lbs. ________________ kg.

Efficiency: = load supported (g.) =

mass of Bridge (g.)

(Show efficiency in all units)

Abbreviations:

oz. = ounces g. = grams lbs. = pounds kg. = kilograms

in = inches cm = centimeters sq. in. = square inches

conversions:

1 ounce = 28.35 grams

1 pound = 0.45 kilograms

1 pound = 16 ounces

1 inch = 2.54 centimeters

Grading Rubric*Include this sheet as the first page of your Report

Name: ________________________

Overall Bridge Project Grade:________

Build Grade (20%): ___________

How well your Bridge is built. Are all the joints squared up and joined straight? Does the Bridge stand straight? Is it level?

Report Grade (80%): _________

(Sum of the following 3 items, 25 pts for 100%)

Write up (30 pts): ________

Are all items asked for in the write up included?

Design Analysis (20 pts): _______

Are all the measurements and calculations done correctly showing proper units.

Plan Drawing (30 pts): ________

Are the side, top, and end drawings done?

Is it neat and square? Are the lines straight? Are the dimensions correct?

Are the layers color coded with a legend?

Is the overall height and width top and bottom of the Bridge labeled on the plan?

Is there a detailed expanded view of the joint arrangement?

Point Deductions: ___________

Reason:

Joining Wood Sticks, Flush vs Layered