Can't Believe Your Cantilever

 

      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!

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Supplies:

 

A 3" piece of clear, flexible tubing

(ask at a hardware store)

20 strands of uncooked, unbroken spaghetti

Masking tape, 12"

Measuring tape

 

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 falls?

 

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 get.

 

            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 building idea.