1. Investigation Part 2
Mental Models

2. Define: Linear relationship: Linear Equation: Mental Models:
A relationship of direct proportionality that, when plotted on a graph, traces a straight line
A first-order equation involving two variables: its graph is a straight line in the Cartesian coordinate system
an explanation of someone's thought process about how something works in the real world.

3. What information do you need to write an equation for the line that represents the relationship between the thickness of the bridge and the weight it can be?

4. Investigation Part 3
Design and Creation

5. Truss Bridge
A truss bridge is a bridge whose load-bearing superstructure is composed of a truss.
This truss is a structure of connected elements forming triangular units.
Truss bridges are one of the oldest types of modern bridges.

6. Truss Bridge

7. Suspension Bridge
A suspension bridge is a type of bridge in which the deck (the load-bearing portion) is hung below suspension cables on vertical suspenders. 
This type of bridge has cables suspended between towers, plus vertical suspender cables that carry the weight of the deck below, upon which traffic crosses.

8. Suspension Bridge

9. Arch Bridge
An arch bridge is a bridge with connecting structures at each end shaped as a curved arch.
Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side.

10. Investigation Part 2
Part B

11. Mackinaw Bridge

12. Location: Type of Bridge Length of Bridge: Mackinaw Bridge
Mackinaw City
Type of Bridge
Suspension
Length of Bridge:
5 miles
What type of bridge is this?
What shapes do you see?
Would this be a good design for your popsicle stick bridge?

13. Kintai Bridge

14. Kintai Bridge Location: Type of Bridge Length of Bridge: Japan Arch
200 m (0.12 miles)
What type of bridge is this?
What shapes do you see?
Would this be a good design for your popsicle stick bridge?

15. Bollman Truss Railroad Bridge

16. Bollman Truss Railroad Bridge
Location:
Maryland
Type of Bridge
Truss
Length of Bridge:
160 feet
What type of bridge is this?
What shapes do you see?
Would this be a good design for your popsicle stick bridge?

17. Investigation Part 2
Part c

18. Bollman Truss Straight square frame Very strong at short distances
Simple design

19. Allan Truss Uses triangles as support Very strong at short distances
Simple design

20. Brown Truss Straight square with triangles inside frame
Very strong at short distances
Simple design

21. Baltimore Truss Triangular frame with many triangles for support
Very strong at short distances
More complex design