What is the term used when water or any liquid is above the level of the top of a glass without spilling over?
water fills a glass, yet at some point it will spill over. just before that point, the water is actually above the rim of the glass… what is this called?
FuzzyFerret
on February 8th, 2012
Surface tension keeps the water from spilling over. You can also float a metal sewing needle on the surface tension of water. If you search you will find all kinds of fun experiments that have to do with surface tension.
ToxicSkull
on February 8th, 2012
Surface tension.
Style
on February 8th, 2012
Surface tension.
WyleCoyote
on February 8th, 2012
Surface tension is what makes this phenomena possible.
SkateRForeveR
on February 8th, 2012
Convex meniscus caused by surface tension.
Fractalfallout
on February 8th, 2012
Adhesion.
Look at water on a penny, the water molecules are sticking together because of the molecular bond.
ontheplains
on February 8th, 2012
The SURFACE of the water (essentially FLAT in the middle, but CURVED over and downwards towards the rim at the edges) is called the MENISCUS. It is indeed DUE TO the existence of SURFACE TENSION, but it itself is not CALLED “surface tension,” as others have mistakenly asserted. (In other words, that’s the REASON for the phenomenon, but it’s NOT th eNAME of the phenomenon itself.)
My old 1950′s English Grammar School (= U.S. High School) Physics Master (God bless his long-transported soul) used to regularly intone the following mantra as he strode betweeen the lab. benches:
“Always measure the level of the meniscus!”
What that mantra implied was that the curved edges of any liquid were a very small edge effect, so that a much more accurate measurement of any critical volume in an experiment was the volume implied by the level of the “flat bit.”
Incidentally, before the effect mentioned in the question comes into play, which occurs when surface tension is holding back the last bit of water before the surface itself “breaks,” and the water overflows the edges, the surface of water actually curves UPWARD at the edges. You can easily see this if the water is in a glass beaker or a vertical “graduated” glass cylinder. In contrast, mercury (which we lovingly played with and chased along the lab. desktops until it was decided that we were in mortal danger) curves DOWNWARD. This difference is the reason why Mercury on a polished table or desktop essentially gathers into little, almost bead-like spheres which will skittishly roll around as they are blown and/or pushed with only the slightest effort.
Thanks for the memory.
Live long and prosper.
Grapes
on February 8th, 2012
It is known as SURFACE TENSION.