Bridges

What are the forces acting on this simple beam bridge?

What are forces?

Force

PULL PUSH

Force has both

magnitude and

direction

What is gravity?

F(g)Pulls Wiley down

F(g)= maForce is measured in

N (Newtons)M= Mass

A= Acceleration of gravity or 9.8 m/s2https://www.youtube.com/watch?v=JlLSc3tZAyc.

F(n) pushes up

F(g) pulls down

Forces need to be in balance for something like YOU or a static Bridge to stand at rest

7/8 grade

https://www.youtube.com/watch?v=aJc4DEkSq4I&feature=fvwrel

Bridges

For many hundreds of years humans have used bridges to traverse difficult geographical terrain

Our species wasn’t the first to do this….

http://www.youtube.com/watch?v=IBTjQMtbViU&feature=related

Ant societies have division of labor, communication between individuals,and an ability to solve complex problems.

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..

The even distribution of forces is what keeps our modern day bridges togetheras well

Video of an ant raft barely clinging togetherhttp://www.youtube.com/watch?v=L2ZysgGAABw&feature=related

Tension forces PULLING OUT

Compression ForcesPUSHING IN

You Be the

ANT!