Cantilever Beam

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

Pizza Slice- A cantilever beam: