what is effective mass ?
145098
In solid state physics, a particle's effective mass is the mass it seems to carry in the semiclassical model of transport in a crystal. It can be shown that, under most conditions, electrons and holes in a crystal respond to electric and magnetic fields almost as if they were free particles in a vacuum, but with a different mass. This mass is usually stated in units of the ordinary mass of an electron m
508636
same mass, same weight
1008206
Mass has energy equivalent values but to blindly say that enegy has mass is not necessarily correct.  When an atom is in tact, it has a certain mass but if you break it down into its constituent parts, you will see that the sum of the parts is less than the whole.  This is accounted for in what is called the mass defect.  This mass defect is the binding energy required to hold the atom together against the reulsive forces of like charges located in the nucleus (protons).  As an atom gets bigger, the mass defect will also increase (up to a point)
578713
U can a measure the mass of an object accurately using a Physical Balance.\nUnit of mass is kg in SI unit ysstem.\nMore accurate ways of measuring mass is done now.\n\nU can calculate it's weight by a formulae:\nW=mg.\nW-Wieght\nm-mass\ng-aceleration due to gravity (9.8 ms^-2)
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It has no mass. But it has relative mass of ≤ 1. It is a matter.
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The net external force acting on a particle is equal to the product of the mass and its acceleration.\n\nF = ma\nwhere, F = the net external force\n       m = the mass of the particle\n       a = the acceleration of the particle
26899
go to encarta.msn.com and search for keys mass/solid structure, surface Structure
89835
In terms of mass.\nThe SI unit for mass is the kilogram (kg).\n\nDo not confuse mass with weight, they are not the same thing.  The mass of an object is constant throughout the universe where as weight is a vector force that depends on the gravitational field around the object.  It is unfortunate that these two words are used interchangably sometimes.
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Mass  - Involving a large number people.\n\nDensity - The quality of being dense.\n\nVolume - Amount of space occupied by a substance, liquid, or a gas.
365615
Have mass and occupies space
609337
The atomic mass of a chemical element is the mass of an atom at rest, most often expressed in unified atomic mass units. The atomic mass is often synonymous with relative atomic mass, average atomic mass and atomic weight; however, it is subtly different in that it can either be the abundance-weighted average of isotope masses of an element or the mass of a single isotope.\n\nThe relative atomic mass (also known as atomic weight and average atomic mass) is the average of the atomic masses of all the chemical element's isotopes as found in a particular environment, weighted by isotopic abundance. Periodic tables usually list these with reference to the local environment of Earth's crust and atmosphere. An uncertainty in parenthesis is often included. For artificial elements the nucleon count of the most stable isotope is listed in brackets as the atomic mass
135498
If you mean the mass of the spring itself, then that is a bit more complicated than most elementary physics covers. Most elementary physics assumes massless springs, in which case the answers above are correct. \n\nFor a spring with mass, one has to think.\n\n--------\n\nSome people have worked this out. An approximate solution is the frequency is sqrt(k/M*) where M* is the effective mass. If m is the mass suspended by the spring, and M is the mass of the spring, then M*=m+cM where c is about 1/3.\n\nMore accurate estimates are possible. For example, c>1/3 always, but as m>>M, then the value c=1/3 is approached, and when m=0, the limiting value of c= 4/(pi^2).
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atomic mass is, well the mass. also the number of protons + neutrons. Atomic number is the number of protons, which is also the number of electrons
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I suppose mass is a fairly easily measured value. Compared to finding the number of atoms, it's easier to just stick a sample on a scale/balance and weigh it.\n\nAnd the masses provided on the periodic table are weighted averages of the different isotopes found in nature.
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No common denominator for the energy in the things you mention except that if it has mass, then it embodies the energy given in E = mc^2\n\nThis applies to ALL matter.
824559
Mass is measured in grams.
845623
no, mass and weight are not equivalant but they are related to each other according to:\nw=mg\n\nand mass and energy relationship is:\nE=mc2\nwhich means mass is one type of energy itself\n\nNotice that g is not a constant while c is.