Can't Believe Your
Today's Snack: Grab a
handful of uncooked spaghetti about one-fourth inch to one-half inch in
diameter. Drop into boiling water for a few minutes. Strain. Meanwhile, heat up
some bottled spaghetti sauce to toss it with. Top with a few shakes of Parmesan
cheese. Pass the pasta!
A 3" piece of clear, flexible tubing
(ask at a hardware store)
20 strands of uncooked, unbroken
Masking tape, 12"
A cantilever (pronounced CAN-tuh-lee-ver) is something that sticks
out sideways from a vertical support without any bracing. Another word for it
is an "overhang."
An airplane wing is a cantilever.
Big stoplights that stick out over intersections are, too.
You see cantilevered ledges and balconies on buildings,
cantilevered bridges, parts of roofs, flagpoles, diving boards, and other many
other building forms.
What cantilevered structures can you think of, from your own
neighborhood? Your city? What you've seen on trips or in books?
Now let's make our very own cantilever!
First, take a ruler. Edge it out into the space that is off the
side of your desk or table. The surface of the desk or table is the vertical
support, and the part of the ruler that sticks out over the edge into empty
space is cantilevered.
Without holding the ruler down, and pushing very slowly and gently
with your hand, move the ruler more and more to the side, cantilevering out
over empty space. How far can you stick it out over empty space before it
The more rigid, or unbending, the part that sticks out, the
stronger the cantilever will be. But it can't be too heavy for the vertical
support, or it'll crack off.
Let's try to make a cantilevered structure that sticks out
sideways as far as possible, without touching the floor. You'll learn a lot
about the relationship between length and weight as you try to make those
strands of spaghetti stick out as far as you can.
Let's measure how many inches the structure cantilevers. If there
are more than one of you trying this, you can compete!
The end of your structure should be placed in the tube, which in
turn should be attached to the desk or table with the masking tape.
The only place that the spaghetti
should touch anything besides spaghetti, is INSIDE the tube. In other words,
you can't tape the spaghetti to the desk or table. That includes the surface,
sides and legs of the desk or table. But you CAN tape the spaghetti to the
plastic tube, and you can tape the plastic tube to the desk anywhere you wish.
Yes, you MAY break up the spaghetti
and combine more than one strand together.
If your cantilevered structure
breaks, your measurement will be shortened. The spaghetti has to be connected
to other spaghetti or its length won't count. And the 12" of tape is all you
You may tape the spaghetti strands
to each other, and to the plastic tubing, but NOT to anything else, including
the desk, table or floor.
If your structure touches the floor,
you must break off spaghetti until it does not touch the floor.
Once you get your cantilever just as
long as you possibly can, and it's not touching the floor, then take the
measuring tape and measure in inches from the edge of the table or desk, to the
end of the spaghetti.
How'd you do? Good!
Can't stop cantilevering - a great