Is it possible for a system to have negative potential energy?
603335
Potential energy is generally measured from a reference point of your choosing. If you choose the reference point (zero) to be above a point in the systen than you are at negative potential energy.
423664
Potential energy levels are often given as negative numbers.  Potential energy is energy an object has due to its location or state. Two massive objects (a rock and the earth, for example) have more gravitational potential energy the further apart they are: you have to put energy into them to separate them, you can get the energy back out by letting them fall toward each other (potential energy is changed into kinetic energy).\n\nIn the case of an electron, it's potential energy due to its location relative to the positively charged nucleus; the further away from the nucleus, the higher the energy level of the electron.\n\nOK you knew all this already.  The point is that I can define any particular energy level (distance from the nucleus) as "zero".  If the electron is closer to the nucleus, it has "negative" potential energy, if further, it has "positive" potential energy.  It's arbitary; the only thing that matters is the difference between where it starts and where it ends up, meaning the change in its energy level, and that won't change with your definition of "zero" energy level.\n\nSo for convenience, physicists like to define potential energy levels at infinite distance (or separation) as "zero", and all others become negative.  Since these forces (gravity, electromagnetic force) fall off with the square of distance, potential energies at finite (nonzero) distances aren't "negative infinity".
103558
Kinetic energy is almost never conserved. There is friction, and conversion of kinetic energy to potential energy, for example.\n\nI think you are referring to conservation of energy, not kinetic energy. The law of conservation of energy is allowed to be violated but only for very short periods of time, by the Heisenberg Uncertainty Principle.
946151
well, the answer to this is simple.\nthis is because at infinity we assume the p.e of any body to be 0, as force is 0.\nAt distances lesser than infinity (i.e, in vicinity of attraction) the p.e will be lesser( energy decreases with decrease in distance) , which will obviously be negative.\n\ni guess that will help
267868
No.  Obviously life exists despite the second law of thermodynamics.  The chemical processes associated with living organisms use energy from the surrounding evironment to create more order.  Our evolutionary ancestors did that too.  I see no way in which evolution contradicts the second law of thermodynamics any more than the existance of life does.
821839
potential cannot be associated with a non conservative force. potential energy is the energy which is stored inside the body when you do some work against that force. If it is a non conservative force, than the work done to move something to the same point through different paths will be different. Which means that potential at a given point may have more than one value which is practically impossible. That's why potential can never be associated with a non conservative force/field.
961109
It's good to see people actually thinking about what the terms they're using mean, rather than just plugging them into equations.\n\nBasically, the place where you seem to be confused is here:\n\n"In gas such as water vapour, intermolecular forces of attraction is weak and hence it has low PE"\n\nActually, this means the exact opposite, that the system has very high potential energy. Think about gravity for a minute - if a rock placed at, say, 1 foot above the ground were to fall to Earth, it would not release very much energy. Conversely, if the rock were placed 1 mile above the Earth, it would release a considerable amount of energy. The higher the rock is, the greater it's potential energy. However, the further the rock is away from Earth, the weaker the force of gravity acting on it - thus weak gravitational attraction corresponds to higher potential energy. Similarly with the particles in a gas - if they were to "fall" into a partially bound state such as that of a liquid, they would release energy, and thus the unbound state where the particles are too far away from each other to form bonds is the higher energy state.\n\nThis is not to say that a weaker force always corresponds to a higher energy state - if the reason that the force is weaker is that there is less mass/charge/whatever producing it, that really will lower the potential energy. But in the transition from a liquid to a gas does not change the charge of any of the particles - the reduction in intermolecular forces comes from the fact that the particles are moving out of each other's electrical potential wells, a process which, just like lifting up a rock, raises the potential energy.
199784
electrons have negative charge
875999
Yes, I believe houses, and objects like furniture can hold negative energy, kind of a "cell memory"  the place may just need feng shiu, rearranging things so the energy flows properly. \n\nhttp://www.experiencefestival.com/a/Space_Clearing/id/35197\n\nhttp://www.wholife.com/issues/9_3/03_article.html
497338
Gravitational Potential Energy does. However, there are other types of potentialenergy. For example, a battery has potential electrical energy and that is not dependent upon gravity. The food we eat has potential energy that is not utilized until we need it. Atoms have potential nuclear energy. If you are studying Mechanical Energy....motion, speed and the like then probably you ARE talking only about Gravitational but usually it is labeled as such...GPE.
32356
Consider a system of charges. The charges of the system exert electric forces on each other.If the position of one or more charge is changed, work may be done by these electric forces.We define change in electric potential energy of the system as negative of the work done by the electric forces as configuration of the system changes. Potential energy of the charge particle in an electric field depends on the magnitude of the charge.However, potential energy per unit charge has a unique value at any point in an electric field.For eg. We place a positive charge x Coulomb at a point in an electric field where particle has an electric potential energy of y Joule. Then potential energy per unit charge is =x/y J/C(Using unitary method)\nIf we replace our charge by another charge of magnitude 2x Coulomb.We would find that the second charge has a potential energy of 2y Joule.Potential energy per unit charge would be same.Potential energy per unit charge is independent of the charge we are using.\nThe potential energy per unit charge at a single point in an electric field is called the Electric Potential.Now the difference between the Electric Potential between two points is called Potential Difference between those two points.\nPotential difference is directly proportional to current.(Ohm’s Law)\n\nFor further queries e-mail me:  trust_amplifier@yahoo.com
1041749
Not as far as I know. I'm currently studying Physics at Uni and  studied thermodynamics last year. Negative Kelvins don't really make sense - 0 degrees Kelvin is a sort of absolute zero in terms of temperature.\n\nScientists still aren't able to cool anything down to 0 degrees Kelvin (approx. -273.15 degrees Centigrade) and have only come as far as about one hundredth of a degree, if I recall correctly.\n\nIf anyone gets a negative result in Kelvins, they most likely have done something very wrong. Either that or the person has miraculously solved one of science's biggest problems. :D If so, I suggest you go on to discovering the United Theory.
91593
yes.as b has something raised to power negative.it goes to denominator
547508
No. \nThe system is static and the sum of the forces equal zero, but there definately are forces flowing through the bar.  Replace the bar with a piece of plastic and then what happens.  The system is no longer in equilbruim, becomes dynamic and the plastic gets torn to shreads.  The same would be true if say you used a piece of wire.  Just because something is not moving does not mean there are no forces flowing through it.
938332
I think you mean at the atomic level, but still the answer is no.\n\nOne counter example would be positronium. This is when an electron and its anti particle, a positron, "revolve" around each other.  This is very unstable with a half-life of about 10^-7 seconds. \n\nThere are other exotic atoms of this type. Any atom formed by a particle and its anti particle is called an onia.
347168
Energy that enters the system from the surroundings.
506358
an energy oscillation