Book Shelf Blues
You ordered a new collection of Encyclopedia Britannica and it just arrived today! You are extremely proud of this new collection and want to display them for all to see. You start setting them on a shelf you just installed on the wall. After you put about 5 of the large books on the shelf, you see it starts to sag under the weight. That will never do! You refer to your knowledge of tension and compression and figure you need some extra support to withstand the weight of the books! You decide to support your shelf with two diagonal wooden beams that will make triangles underneath the shelf. It looks something like this:
The areas of tension and compression have equal and opposite strengths, which stabilize the whole structure. After properly installing these support bars, your bookshelf can hold all the books!