Law of conservation of mass?
595034
A school student?\n\nNike and one other are very thorough.\n\nSimply:\n\nMatter can neither be created nor destroyed in ordinary chemical and physical changes, though matter may change its forms or shapes.\n\nExamples:\nPhysical Change of conversion of ice into water or vice verssa. The total mass remains constant.\n\nChemical change of burning of wood apparently shows loss of mass of wood when we find ash but if this change is brought in a closed system the weight of the system will remain unchanged.\n\nIn simple total weight of wood and oxygen will be equal to the total weight of ash, CO2, water vapors and other vapors of organic and inorganic substance coming out as a result of combustion.\n\nThere are two exceptions:\n\nIn nuclear reactions some of the mass of the substance, (radio active substances in present science of experiments) converts to energy and so mass is lost. But this change is on such a small scale that the change of mass can not be noticed. \nThe conversion of mass into energy is governed by the formula E=MC2\nApply the values say for 0.001 gram of mass.\n\nThe other exception is change of mass in bodies approaching velocity of light. This is yet theoretical as man has not been able to achieve such high speeds.
857646
I found no reference to "inertial motion."  Did you mean inertial mass (m)?  There is also the concept of motion in an inertial frame; perhaps that's what you meant.  [See source.]\n\nAn inertial mass is simply one that fits into the equation F = ma.  (There is also a gravitational mass that fits into W = mg; where W is weight and g is the acceleration due to gravity.  Einstein claims the two masses are equivalent.)  Because F = ma has been proved over and over again, even in high school labs, I think it's safe to say that m does exist.\n\nThe conservation of energy and of momentum laws are two major uses of inertial mass.  These two laws have been proved over and over again; this also validates the concept of inertial mass.
978453
With Boyles law, doubling the pressure doubles the mass. No sure what the relative masses of air and helium are, but let`s say it`s 10 to 1, then 10x the pressure is what you need
979053
Mass is always mass in any situation. You can´t change the mass, you only can change some properties of the mass, such as, weight (according the gravity), quantity of cinetic energy (accordind the velocity of the mass), etc. But the mass is always the same mass!!!
1161161
The law of conservation of momentum applies in all cases.\nFor a given system, the initial momentum must equal the final momentum.\n\nIn your example, we can define the "System" to be the combination fighter plane + bullet.  If we call this initial momentum P, then at any time after the initial conditions, the sum of the momentums of all parts of our system must add up to P.\nWhen the bullet is fired foward, the fighter plan slows down to compensate and conserve momentum.\n\nMomentum (P) = mass (m) * velocity (v)\nP = mv\n\nThe bullet's mass is very tiny compared to that of the fighter plane, so even a large increase in the bullet's velocity would only mean a small decrease in the resulting velocity of the plane.\n\nIf you call the bullet's mass, m_1 (with final velocity v_2) and the plane's mass m_2 (with final velocity V_2),\nwe know that,\nP = m_1*v_1 + m_2*v_2\nif P_1 goes up, then P_2 must go down by just that amount.\n(delta P_1) = - (delta P_2)\nm_1 * (delta v_1) = -m_1 * (delta v_2)\nsince we assume the mass stays constant,\n(delta v_2) = - (m_1 * delta v_1) / m_2
581268
The mass of any body changes with velocity.\n\nIf the masss of the body is m0 when it was rest, then the mass ,when the velocity is v, is  m =m0/ square root of {1- (v/c)^2}.\n\nThe momentum is  equal to mv which is greater than mov
895025
no. there is no such case , theroretically. because, according to the law of conservation of energy the total energy in any closed system is constant. however practically some energy is dissipated in a practical case.
816057
again ... conservation of (mechanical only here) energy\n\npot energy = kin energy\n\nmgh = 1/2 m V^2\n\nso V = sqrt(2gh) -- see mass irrelevant\n\nV = sqrt(2*9.8*8.53) = 12.9 m/s\n\ng=9.8m/s^2 is the acceleration due to gravity\n\ng=10m/s^2 is not a bad approximation
1007966
yes, the mass of water/ice does not change during a phase change, only the density and thus the volume. Law of Conservation of Matter.
292932
As others have said, it's relationship between energy and mass.  However, there are a few additional points about it which are interesting.  The mass here is the rest mass, the mass of an object when it is at rest relative to the person doing the measurement.  Some things, like photons, have no rest mass.  Their energy is give by E=(h-bar)(nu) where h-bar is Planck's constant divided by two pi, and nu is the frequency, in rad/sec, not Hertz. Additionally, E=MC^2 isn't the total energy for a particle, it can also have kinetic energy if it is moving with respect to the observer.  So, it's really E=MC^2+KE, where KE is the kinetic energy of the particle.    \n\nYou can also switch it around and consider that the mass, M is equal to the total energy divided by the speed of light squared.  In this case, you can calculate the mass for things which can vary based on the energy the object has, and not just the rest mass energy equivalence, but also the kinetic energy.  This is where much of the mass consumed in a nuclear reaction comes from.  Reorganization of nulcei to lower energy states gives them a lower mass, since the total energy is lower, and this change in mass is released as energetic radiation.  So, the core of a nuclear bomb contains ~ 10 kilos of highly enriched uranium, but only a tiny fraction of that is consumed in the explosion.  If all ten kilos were fully converted to energy, it would be enough energy to destroy the earth.  Instead, a tiny fraction of a gram is consumed when the nuclei undergo an out of control chain reaction, reogranizing and spitting out radiation, which destabilizes and causes the reorganization of neighboring nuclei, and so the reaction proceeds until most of the nuclei in the bomb core (called the "pit") have reorganized.  By this time, it's exploded and it would be very difficult to reassemble and weigh all the atoms left over from the reaction, but, if you could, you'd find the total would be less mass than the 10 kilos you started with.  \n\nChanges in mass when energy is absorbed or emitted is actually true for things other than nuclear reactions.  If you're running past me at 5 kilometers per hour, you actually weigh more than if you're standing stationary next to me.  However, given that the conversion ratio between mass and energy is the speed of light squared, which is a very large number, the amount of mass you gain by running at such a low speed is so small as to be unmeasurable.  Only if very large amounts of kinetic energy are involved does it become important.  If you were to fly past me at nine tenths the speed of light in a spaceship, and I could measure your mass as you passed, by, say, deflecting your path by bouncing something off you to see how much acceleration you gain for a given amount of force and using F=MA to calculate your mass, I'd find that you had a significantly higher mass.    \n\nSo, the simplest form of the statement, the one which calculates just the rest mass/energy relationship, is only part of the importance of this equation.
460675
We dont even have a machine with efficiency close to 1, you are talking of a machine of efficeincy 2 or more. What of the law of conservation of energy, and mass and momentum?\n\nI don't think it's possible, not in this universe within the limits of the known laws of Physics.
1042891
They don't call it a Law for nothing you know.\nWherever you look, you will always see an action-reaction paired up.  Newton's 3rd Law fits nicely in with another law which we know holds true in all cases...the Law of conservation of momentum.
963983
There are many ways to do this problem.  The best way to probably handle density, and perhaps mass even, is using Archimedes principle of buoyancy.  You can find a detailed discussion on www.wikipedia.com and search for Archimedes or buoyancy.  The main idea is that "the weight of the displaced fluid is directly proportional to the volume of the displaced fluid".  \n\ngood luck!
468574
The conservation of energy rule in physics dictates that energy is always conserved, so it can't be destroyed merely changed to another type. Perhaps an example could be in a crash, the kinetic energy is turned into sound and heat energy primarily, but the energy still exists.
1080952
mass, volume and temperature.
666644
I don't know how so many people are confusing the first law of motion with the second law of motion. People, she's asked for the second 'theory' of motion, which is to be understood, of course as the second law of motion. Which states that the rate of  change of momentum is directly proportional to the impressed force and takes place in the direction of the force. \n\nThe proof of that cannot be derived from first principles, as it is one of the first principles itself. Of course, for a special case in which the system mass is constant, it does reduce to F = ma, but that is really elementary.
509753
Mass is the measurement of matter, usually in grams,\nkilograms, etc.\n\nMatter is any material found in the universe that is in one of three states- those being gas, liquid, or solid.\n\nThe law of conservation of matter and energy includes the\nassertion that there is a finite (limited) amount of matter and energy in the universe.\n\nMatter can be converted into energy (example: the sun\nconverts its matter into energy continuously in the process\nwe call nuclear fusion).