Weston Middle School
Technology/Engineering Course Materials
Materials: Paper Sheet, AA batteries, tape
Fold paper lengthwise twice
Holding paper at one end, try to support battery on other end -
- Held horizontally( flat)-- you can't
- Held vertically- you can
- Why?(Discuss)
- Force downwards causes
compression in top of beam, and tension in bottom
of beam
Downwards force becomes a sideways force, resisted by the tensile strength of the beam—structural beams have wide flanges to provide extra material at point of greatest stress, and little material in middle (web) along the neutral axis, where forces are minimal
Revised
January 2015 by Jonathan Dietz,
dietzj@weston.org