This is a good question for IO.

Problem definition:

When chairs are pushed on the floor in room #2, they make a lot of noise.

Analysis:

First of all, we must find out why the chairs make a noise.

As the chair is pushed the leg resists sliding because of friction between the leg and the floor, but if enough force is applied, the chair finally moves.

Even though the chair leg seems very stiff, it actually bends a little as you push and then once it starts sliding it snaps back. It's this bending and then snapping back motion that causes the noise. Run your finger nail down the teeth of a comb, that's sort of what the chair leg is doing. The leg vibrates at a very low frequency.

Proposed solutions:

1. Make the legs very very stiff so that they won't bend.

2. Lift the chair instead of sliding it.

3. Reduce the friction between the leg and the floor.

Practical solution:

Place socks on the ends of the legs.

This will reduce the friction and thus the noise. Ask students to bring in some of their odd socks, you know, the ones that have lost their mates somewhere between the washer and the dryer. After all, they don't have to match. To keep the socks on the legs, since they're much skinnier then your feet, wrap tape or elastics around the top.

Now it will be so quiet it your classroom that you'll have to find something to keep everyone awake.

Answer #% % filename A170.DOC page% % page 1 of% % numpages 1 % % date \@ "MMMM d, yyyy"June 2, 1996

€2, Miss Breeze

This is a good question for IO.

Problem definition: