Why does the pitch of the clinking spoon stirring a cup of coffee continue to rise as you stir?
338249
because the liquid you are stirring is being changed chemically,\nbecause what you are stirring in is becoming 'part of'\nthe liquid in the cup therefor it changes the exerted pressure on the inside of the cup which in kind changes the harmonic resonance of the cup, hence the change in pitch of the clinking. you can test this by stirring your coffee before you add anything and then after/as you add your sugar and/or your creamer
790288
This is due to the Doppler effect. You know how when a car is coming towards you it has a higher pitch sound, and when it is driving away from you it has a lower pitch sound? This is called the Doppler effect, and it basically works like this:\nSound (and light) are waves that are emitted by the source (in this case the car, and as the source travels towards or away from you, these waves bunch up (towards) or spread out (away). This bunching / spreading causes the waves to interact with eachother. Basically, if the source is moving away the wave's frequency decreases (so the sound is lower) and as the source moves towards you, the frequency increases (so the sound is higher). It works the same with light (red for lower frequencies, blue for higher frequencies).\nSo, does this mean that all the stars out there are moving? Hell yeah! And they're moving pretty fast, too! The vast majority are moving away (so most are red-shifted), bt a few are racing towards us, so they are blue-shifted. The light from the big bang that created the universe itself is moving away from us so quickly, it has shifted past red and all the way to the microwave spectrum (yup, that stuff you use to reheat your morning coffee), and appears as background radiation.\nHope this helps.
848058
Capillary action.  The smaller the diameter of the tube, the higher the liquid will rise.
828737
Try to spin a boiled egg on its side,it will stand up after a while.Why and how?
825037
For the cork to sink it must raise the water level. Since it must raise the water against the force of the centrifuge - pushing harder on both just doesn't do the job (of sinking the cork).
1180164
The physical mechanism is unknown, but possibilities that have been suggested include:\n\n   1. cavitation within the joint – small cavities of partial vacuum form in the fluid then rapidly collapse, producing a sharp sound (hypothesis in a medical journal)\n\n   2. the sudden stretching of ligaments (hypothesis by one reader of that journal)\n\n   3. release of gas from the joints being adjusted (this applies to the popping that can occur in any joint such as during chiropractic manipulation)\n\nFeel free to read more at http://en.wikipedia.org/wiki/Cracking_knuckles
931176
I guess that where you tap the cup is important. The ringing sound will be generated by the energy you put in from the tap. The tone is dependent on the internal volume at the point where you tap, and the thickness of the cup where you are tapping.\n\nIf it were a cylinder I guess that it would produce an even tone all over, maybe you should try that?\n\nFar from being boring this is an interesting question about harmonics, I am off to the kitchen, with a spoon...
1177517
By rubbing the lip, you're vibrating the glass. When you rub it at the right speed, it stars vibrating at its resonant frequency, and it makes that noise.\n\nThe resonant frequency of an object is kinda like a swing. If you push and pull at the right time (the resonant frequency), you can make the swing go higher and higher. If you push at the wrong times, you're not going to get anywhere.
299380
The frequency of the sound wave determines the pitch.  When you speed up a recording, you are increasing the frequencey, so pitch rises.  The reverse happens when you slow down a recording.
1092265
You know how when you suck on a straw you get your drink to move up through the straw? This happens because by sucking, you are creating a partial vacuum on one side of the straw, and the atmospheric pressure on the liquid on the other side, now having nothing to counter it, pushes the liquid up through the straw. But no matter how much you suck, you cannot reduce the pressure on your side of the straw to less than zero (i.e. a complete vacuum), and as such there is a maximum height to which you can raise a column of water - that height depends solely on the atmospheric pressure on the other side of the straw. This means that you can construct a barometer simply by having a glass tube immersed vertically in some liquid, and pumping out all the air on one side of the tube, and then sealing the tube - the height of the liquid then gives you the ambient air pressure. Water, however, is not very dense, and so your barometer would have to be very large if it used water. To get around this problem, scientists use Mercury, which is a much denser liquid, to measure the pressure. A pressure of 1 mm Hg is simply a pressure that can support a column of Mercury 1 mm high under this arrangement.
111649
I don't have an answer for you except that it has something to do with the softness of the lead, I think.  But that made me laugh, so thanks for that, and thanks for the 2  :-)
478046
Only on the concave(front) curve of the spoon will give an upside down reflection.  The distorted surface of the spoon reflects light from yourself at angles which result in an inverse image in the spoon.  This is actually called refraction.
123323
Yes, by requiring to move the woofer with more ampltitude, requireing more force and thus more energy.  An interesting note is that most of the 'extra' energy required for the louder sound is not converted into sound...There is very little energy in sound.  I have read something where it would take over 8 years of 'shouting' to heat a cup of coffee.
368951
Same phenomenon happens when you look through a convex lens or at your reflection in a spoon. Something to do with the movement of light. It bends and shows stuff the other way around. Sorry, it's not my expertise. But that's basically how it happens.
494151
It's bernoulli's principle. Fluids have a lower pressure when moving than when still. Since the water is moving past the spoons (which act like the wing of a plane) they feel a pull from the pressure drop and come together. Try it with a peice of paper sometime. Roll a piec of paper up so when you place it on a flat surface it looks like a curved bridge. then blow under it and it will collapse instead of blow away. It's pretty neet.
269390
When you rub your wet finger over the rim, you're vibrating the rim. Sound is just vibration of air, so if the resonant frequency of the glass is right, it will make a clear tone.
704288
Depends on the liquid, generally it is transfered from the bottom of the glass into the bottom of the liquid, but some of the heat will transfer up the tube as well.  Best bet any witch way is to angle it a little, and keep it pointed away from you and anyone else, agitate the liquid to help keep the heating even either by rocking it by hand or through the use of a spin vane.