What physics project can I incorporate on different types of strings,  and the sound quality of it?
483991
You can use different string instruments or you an even use different types of strings. Rope, nylon, thread and use different tensions with them.
376476
The very reason that a violin produced a sound is a feat of physics and dynamics that goes above the heads of 85% of college-educated people, much less the world.\n\nLearn about frequencies, resonances, wavelengths, and the like.  Then see how these can be altered by a 1/100th inch movement of a string.\n\nThen ask your question again, and see if you cannot answer it yourself.
172816
It's not a string... I'd say woodwind, but you don't have reeds and such... But it's probably closest to woodwind.
49964
It sounds like you've got quite a project, and little time to do it. I've included a couple of links about speakers and how to make a "home made" speaker out of cardboard and copper wire.\n\nIf the object is to make a speaker with a 'coil', the second link is the one for you. However, if you simply need to make an "amplification" device, check out the 4th link, on the page it's called "Getting in the Groove", and makes a sound using an old record player/ record.\n\nBest of luck.
693418
Well see as though you dont really have much time for a project that involves a control... But here is an awesome listing that has loads of ideas with explicit instructions not to mention material list for a wider variety of projects. Since I have no clue what realm of science you were intrested in... This has a little bit of them all! Good Luck!\n\nhttp://school.discovery.com/sciencefaircentral/scifairstudio/ideas.html
364559
I'm going to assume that you are asking which of the two materials you listed are best at absorbing sound vibrations.  There are many methods, the two you listed are valid, albeit a bit primitive, but the link that I have included below may help you much more.  (Cork soundproofing can be quite expensive, btw.)
564490
There is a program called FRUITYLOOPS that you can use to create tracks of music, wave & audio file samples.  Find the latest version of it or at least V5.1 and better.  It may take a few attempts to make something but it really is an amazing product.
1031070
I was going to say something witty, but the guy above punched in first.  All hail Mr. Answer!\n\nAs for mechanical projects- that's pretty broad.  Narrow it down- like a mechanical concept you'd like to demonstrate, or a function you'd like to preform, and we'll try to help.
517188
It is possible to encode sound into light, send it through space, then decode it back into sound.  You can do this by using the amplitude modulation of light.  Basically, you make the light "wiggle" and it then has a pattern of the sound vibrations.  See my sources for complete details.  It also explains step by step how to build such an apparatus.
767041
Trying to make a string stop vibrating.
237469
The correct word is "timbre".  That is to say, quality.  Consider middle C played on a piano and a violin, with the same loudness.  Same loudness = same amplitude; same pitch = same frequency.  Yet they sound different, i.e. the timbre or  quality is different. \n\nADDITIONAL INFORMATION: In string and wind instruments, progressive waves (transverse in strings and longitudinal in wind) travel outwards in opposite directions from the point where the vibration was started.  When they reach the end of the string or pipe, they are reflected back inwards.  Interference occurs between the outwards and inwards waves and a standing wave is produced.  In this, certain points called nodes (N) are always at rest, while others mid-way between each pair of nodes are in continuous vibration with maximum amplitude; they are called antinodes (A).  The distance between two consecutive Ns will represent the half wavelengths in your question.\n\nVarious standing wave patterns can be produced.  If there is a node at each end of the string or pipe and just one antinode between them, the standing wave has one loop and the fundamental note is emitted.  If there is more than one loop, overtones are produced.  It is these overtones (when added to the fundamental) that give a sound its timbre or quality.
73023
A classic, but great visual experiment is sucking a hard boiled egg into an erlenmyer flask.  It is done by using the principles of the kinetic theory of matter.  \nAnother cool project might be doing something with dry ice.  Find a place that you can get dry ice and do fun stuff with it, like create smoke, put bubble solution in water and then drop in dry ice to make bubbles that, when you pop, let out white smoke.\n\nAnother idea might be to do some cool colorful reactions.  Make some dye molecules or something.\n\nHope one of these ideas works for you.
332321
It contains 2 parts.\n\n1. Vibrating string produces sound\n2. Vibrating air column produces sound\n\nThe string vibrates and also forces the air inside the guitar to vibrate. Both combinely give the sounds.\n\nFor strings, the frequency depends on 2 factors - tension in wire and lenght of wire. The tension is changed by tightening the screws and lenght is varied by placing finger at different places.
436127
depends on what you want to do with the sound, but generally they use geometry to create sound friendly environments. (feedback reduction,  good resonance reverb, noise reduction, and others)
1052452
make anything out of the following\nperiscope\nvolcano (Although I don't suggest this - it is a very old project and maybe many will turn up using this)\nA mini hovercraft or hot air baloon (info can be found on net)\nI don't know what it is called but if you know that thing in which we have to take a small hoop across a wire (which is not straight) without touching it. If touched, it will make a sound.\n\nIf none of this suits you, you might watch Backyard Science at National Geographic Channel
524826
Try this free midi + audio track software\nhttp://www.anvilstudio.com/
850553
Start out with a classical with nylon strings, its kinder to teh fingers!  :D