1. Bridge Challenge
Hedrick Middle School
2017

2. The Challenge:
Build a bridge that will span 60 cm over a “canyon” that is 13 cm high.
Design your bridge so that it will hold the maximum amount of weight without any bending or twisting.
Think About It … Which style will work best for our challenge? What forces will we have to worry about? What other design features we will need to include?

3. Structure Requirements:
Must be at least 60 cm long.
Must be at least 9 cm wide.
Must have a smooth road bed and allow a 16 cm tall vehicle to move freely along the length of the bridge.
Bridges may be attached to the sides of the canyon with tape (as long as groups have enough tape left to do so).

4. 9 cm
16 cm
13 cm
60 cm

5. Competition Rules:
Each team will be provided with a junk box filled with materials that may be used to build a bridge.
Each team will receive only one set of materials.
Teams may use all or part of the materials provided but cannot share or trade materials with other teams.
Scissors, glue, and rulers will be provided.
Teams will be given 2 days in class to build and test their bridges. After the time is up, all bridges will be impounded and no changes will be allowed!

6. Testing Procedure:
Teams will begin testing using an empty vehicle. The vehicle must be pulled over the complete length of the bridge to be counted as a successful trial. If the bridge supports the empty vehicle, team members will add more mass and continue the testing process.
At the time that the bridge fails to support the vehicle and the load, testing will be done. Bridge failure is defined as:
Breaks in the road bed or structure that prevents the vehicle from further travel
Significant twisting or bending (creating unsafe conditions for the vehicle)
Vehicle falling off bridge
The team with the bridge that supports the most weight will be declared the winner.
In the case of a tie: the team with the lightest bridge will be declared the winner.

7. Junkbox Supplies
Card stock – 5 sheets Popsicle sticks – 25 Straws – 20 (10 neon, 10 flexible) Paper clips – 10 Pipe cleaners – 10 Rubber bands – 10 String – 3 meters Masking tape – 3 meters

8. Your team will have 2 class periods to create your bridge.
Use the measurements provided to help you design and build your bridge.
Your team will have 2 class periods to create your bridge.
Questions?
Online Stopwatch

9. Skip for now

11. What to do to CLEAN UP: Keep at your tables:
Scissors, Glue, Ruler (in baskets)
Yellow Sheets (under baskets)
Meterstick, box lids
Put all of your bridge materials in your ZIPLOC BAG
Label your bag with your PERIOD and GROUP (table) NUMBER
Bring your Ziploc bag to the STATION FOR YOUR CLASS PERIOD (ex – P1 = Station 1)
Go back to your normal table & pack folders

12. Constructive feedback – be polite, positive, proactive
9 cm
16 cm
13 cm
60 cm
Reminders:
Constructive feedback – be polite, positive, proactive
EVERYONE SHOULD HAVE A JOB at all times!
***Remember you will be evaluated by your group members for your contributions***
Save some tape (if you think you’ll need it) for testing on Monday

13. Get our your GOLD Planning Sheet Clear your tables (binders & folders)

14. Did you get your tape tickets???
Weds, Thurs – BUIDLING
Fri – SCIENCE WORKS
Mon, Tues – TESTING
You will have about minutes on Monday to prepare your bridge for testing.

15. What to do to CLEAN UP: Keep at your tables: Bridge materials:
Scissors, Glue, Ruler (in baskets)
Yellow Sheets (under baskets)
Meterstick, box lids
Bridge materials:
Loose materials in ZIPLOC (labeled with PERIOD and TABLE #) Class period station # (ex: P1 = Station 1)
Bridge pieces (label with names)  STATION 6, 7, 8, or 9
PACK FOLDERS (Bridge Group Table #’s)

16. Strategies for Testing
You will have 5 minutes to prepare and test your bridge.
Talk with your group members about:
Who is going to pull the truck?
How will you pull the truck? (fast or slow)
How will you add weight?
Pennies into cups
Pennies into truck bed
Brass weights (100g, 200g, 500g)
How much will you start with?
How much will you add each trial?
Answer #6 on your gold Planning Sheet.

17. What to do to CLEAN UP: Bring to YOUR TABLE NUMBER’S LAB STATION:
Ziploc bag with unused materials
Bridge pieces LABELED WITH NAMES
Keep AT YOUR TABLES:
Metersticks
Junkbox with scissors, ruler, glue, and yellow sheets
Go back to your normal table & pack folders