1. Physics with Technology
Toothpick Bridges
Physics with Technology

2. Tiger vs. 3.5 Million Toothpicks

3. Image from: www.youtube.com
Goal:
To build a bridge out of toothpicks that can span a given gap and hold as much weight as possible.

4. Materials: Toothpicks Glue Scale Ruler/Meter Stick
Image from:
Image from:

5. Rules:
Spans MORE than 36 centimeters across. (This means that your bridge should be able to go over a 36-centimeter river with no part of it touching the water)
Stands no more than 14 cm tall.
Weighs less than 100 grams.
Has a 1 cm hole in the middle of the bridge and the bridge is not wider than 7 cm.

7. Rules:
You will work in your lab groups, or you can choose to work alone.
Each bridge must be built on the wax paper provided so we don’t have glue everywhere. The paper MAY NOT be part of the structure. The bridge must be able to be lifted off of the wax paper. Paper may not be part of your structure in anyway. This is a toothpick bridge only.
You MUST use the toothpicks I provide and you may not modify them in anyway, including CUTTING THEM.
You MUST use the glue provided by me in class. Use of any other glue will cause you to loose all 15 points in the “followed the rules” category.
You MUST complete this assignment at school. You cannot take it home for any reason.

8. Scoring/Points: Bridge was completed on time:
Strength of the bridge will be determined by taking the load that the bridge held divided by the bridges mass.
Bridge was completed on time:
Bridge followed the specified rules:
Any 1 rule broken, you loose FULL 15 points
Bridge held at-least 1 pound of weight
Bonus Points:
15 points a
15 points a a a
20 points a
(Best Class Bridge, 5 points extra credit)

9. EXTRA CREDIT:
Take: weight held = Biggest # wins
mass of bridge

10. HINTS: Use triangles Toothpicks have more strength vertically
They can hold up to a lb
Show Demo: Pull on a toothpick. It doesn’t break. But can snap it in half with no problem. (Do it). Show them with a meter stick – pull it it and you can pull a car with it, but if you start it bend it horizontally it starts to bend no problem. (Have a student and you pull on it). Show them how it can hold up to a lb.

11. HINTS:
Image from: Alfa img

12. YOUR PLAN:
Draw some diagrams showing your ideas and how you plan to put your bridge together.
Let the students plan and work and sign the sign-up sheet.