1. Bridges

2. What are the forces acting on this simple beam bridge?

3. What are forces?
PULL PUSH
Force has
both
magnitude
and
Force direction

4. F(g)
Pulls Wiley
down
F(g)= ma
Force is measured in
N (Newtons)
What is gravity? M= Mass
A= Acceleration of
https://www.youtube.com/watch?v=JlLSc3tZAyc. gravity or 9.8 m/s2

5. 7/8 grade
https://www.you
F(g) pulls down tube.com/watch
?v=aJc4DEkSq4
I&feature=fvwr
el
F(n) pushes up
Forces need to be in balance for something like YOU or a static Bridge to stand at rest

6. Bridges
For many hundreds of years humans have used bridges to traverse difficult geographical
terrain
Our species wasn’t the first to do this….

7. Ant societies have division of labor, communication between individuals,
and an ability to solve complex problems.
http://www.youtube.com/watch?v=IBTjQMtbViU&feature=related

8. Ants have hooked claws at the end of their legs. They use this to hook themselves together
to make sturdy highways that can carry many, many times their own weight..
Tension forces
PULLING OUT
Compression Forces
PUSHING IN
The even distribution of forces is what keeps our modern day bridges together
as well
Video of an ant raft barely clinging together
http://www.youtube.com/watch?v=L2ZysgGAABw&feature=related