Gravitational Potential Energy

Please note that this flash lacks a punchline because I was too lazy to think of one. In regards to the actual discussion in the flash, it may be incredibly unlikely, but what would happen?! I would like to know the answer, and hopefully someone can answer it!!

38 Responses to “Gravitational Potential Energy”


  • maybe flandre could respond the question ;<

  • …THEN THE OBJECT WILL EXPLODE CAUSE OF ITZ 1337NESS…

    ..and it’s potential energy. :P

  • Well my guess would be that since the universe is good and blown up so its gone and so gravity doesnt exists so potential or kinetic energy doesnt exists anymore.

  • Wouldn’t the individual particles that were left over after the explosion carry their own gravity field so there would still be gravity, just not as strong? Would the ‘object’ suddenly become the ‘ground’ and the smaller particles fall towards it? Yeaah, me acting like I actually know what I’m talking about. :P

  • Maybe the object would be sent zooming in one direction, forever and forever. I think of kinetic energy as a “real idea” instead of a “thing.”

  • What. If everything in the universe explodes except the object, wouldn’t the object just hang there in that one spot?

  • I think the combined gravity from all the smaller items would have the same force as the larger item that they originally composed. The center of gravity for all the particles would remain stationary until they began being affected by forces other than gravity.

  • NoWaiThatsImpossible:O!

    Suika. Suika is the answer for her miniblackholes answers many questions with its vacuum :U

    iono what i just said lol

  • The sum of all energies, potential and kinetic, affects the invariant mass of the system. I believe this makes it so that if you were to initiate a mass-energy conversion of the Earth and universe, save for the object, the kinetic and potential energy would be included in the energy created in the conversion… And thus energy is conserved. However, the chances of this happening are incredibly unlikely. Hooray!

  • The object would accidentally divide by 0 and do a barrel roll at the same time and then…
    and then…
    Flandre Scarlet sneezes.

  • wouldn’t that be called the big bang?

  • I believe the real question KirbyM is asking is if an object with potential energy suddenly has no gravity acting upon it, what happens to the potential energy? Since there is no more gravity, the potential energy the object has becomes 0. However, according to the law of conservation, energy (or mass) cannot just be created or destroyed so the potential energy that was stored in the object must got somewhere.

    I have no idea where though.

  • Potential energy requires gravity. If here is no gravity then it is just an idea.

  • If everything, except the object, blows up/gets destroyed/disappears, then by the law of conservation of energy all the energy will go to the object. Although it might not in the form of potential energy anymore. :)

  • It will probably float endlessly in a void or something..
    where you can divide by zero.

  • well, I think the object would be sent flying due to the explosion… or maybe burnt to a crisp, I dunno lol

  • Well, simply removing the objects will also remove the gravitational potential energy they give to other objects. This does not disobey the law of conservation as that only applies to a closed system, where objects/energy cannot leave or enter the system.

    Oddly enough, the question you’re asking is relatively similar to a situation that physicists have been pondering for a while.

    If an object undergoes a change that affects its gravitational pull on another object far far away, how will this change take place? As in, will it suddenly notice that the forces affecting it has changed? If so, this information could travel faster than light, which would violate quite a few laws.

  • if everything ‘splods, thus removing the potential energy, the explosive force acts on the object, thus turning into kinetic energy. However, without any reference, the object would not appear to be moving. So, that object would experience the big bang first hand. And since no-one knows for sure what happened then, the rest of the theory become unprovable.

  • You could have had everything explode as a punchline.

  • Why do teachers always answer that when they don’t know what to say?

  • @XAnonymous: That actually sounds correct to me… The part about the object becoming the new ground.

  • @: What if YOU are the object?

  • Hmm, “what would happen if the Earth and everything else in the Universe blew up while the particle was in the air and there’s no gravity anymore?”

    See, that’s a badly phrased question – everyone is thinking about the whole Blowing Up bit. The important part of this question is “what would happen if … there’s no gravity anymore?” and you can’t get rid of gravity by blowing everything up.

    Ok, so what would happen if you Switch Off gravity while a particle is falling in air? It no longer accelerates. The conversion from grav. potential energy to kinetic energy is the field of the force doing work on the particle. More kinetic energy = acceleration[1]. However, friction is still around, so the particle would slow down due to friction with air and no gravity to counteract it. Eventually it will just stop and float in air, possibly being jiggled around by random Brownian motion if it was small and light enough.

    Mind you, if gravity was Switched Off, the Earth would be flung away from the Sun, the Sun would be flung away from its centre of orbit… the galaxy would split apart… therefore “everything else in the Universe would blow up”. Yes, so you can’t blow everything up to remove gravity but you WILL blow everything up if gravity is removed first!

    Now how do you switch off gravity? THAT is what’s impossible.

    [1] And then someone will ask “what about geostationary orbits?” The gravitational potential energy is constant in those yet you’re getting acceleration since the direction of velocity is always changing. So don’t take “more Kinetic Energy = Acceleration” as set in hard stone.

  • @Blargel

    >> Since there is no more gravity, the potential energy the object has becomes 0.

    Correct.

    >> However, according to the law of conservation, energy (or mass) cannot just be created or destroyed so the potential energy that was stored in the object must got somewhere. I have no idea where though.

    The Law of Conservation only applies to physically possible scenarios. Gravity cannot be Switched Off in reality, therefore this scenario of “what if gravity no longer existed?” is beyond the jurisdiction of that law.

  • Then that object will become the entire universe… DUH

  • The object would simply continue on its immediate trajectory at constant speed because there would no longer be any forces acting on it.
    Or more likely it would just explode along with everything else. (Not that one can really talk about likelihood in this situation…)

  • reading all these made my brain hurt

  • You can get around the conservation of energy with the fact that removing everything else removes the gravitational potential energy of all other objects in relation to what’s left, and not that object in relation to everything else. By removing the rest of the universe, you’ve removed it’s energy from consideration as well.

  • Oh boy, I didn’t expect actual discussion of physics! Also the focus of the “everything blowing up completely” part was mainly that nothing else would exist, not the actual act of blowing up. Assuming every single particle disappears somehow! Hooray, hypothetical situations that could never happen!

  • Okay, if we assume all other mass in the universe magically disapears in some way the answer is easy.

    If the object was already falling towards earth while earth “goes boom” as Flandre would put it, said object would still move in the direction it fell in the beginning. Because if the gravity just “vanishes” the movement of the object wouldn’t stop, because the accelerating force would be gone, but the object isn’t going to be stopped/slowed down by anything. -> the movement would go on ad infinitum.

    Meaning: The potential energy will simply cease to exist if there would be nothing left that could pull your object towards itself.

  • Please keep up the physics flashes!

    I hate physics, and I need something to make it fun.

  • Well, the potential energy still exist… so the object will continue its trayectory without returning, because it’s the first law of nexton!:
    Quote”There exists a set of inertial reference frames relative to which all particles with no net force acting on them will move without change in their velocity. Newton’s first law is often referred to as the law of inertia.”
    normaly, the gravity will change its trayectory, but without it it will move in the same direction X3

  • I think a few of the posts are mistaking potential energy with kinetic energy. If the ball is falling toward the earth than that energy is kinetic and will be conserved. Potential energy is more of a measurement of the amount of energy being applied to the object. So for example there is a certain amount of potential energy from the gravity of the earth acting on all of us which is prevented from converted into kinetic energy by the ground we stand on, if the ground were removed AND the gravitational force remains than the energy from the gravitational force converts into kinetic energy and we are pulled toward the gravitational center. If however the gravitational force and floor were removed, than the source of the potential energy and thus the potential energy itself would be removed as well, and we would remain motionless. If I’m not mistaken (happens a lot mind you) potential energy is the measure of the interaction of two or more objects so without two or more objects then there is no potential energy to account for.

  • *applauds Psieye*

    That makes the most sense out of all of these comments. And obviously I didn’t pay attention very well in high school Physics if I forgot about the “closed system” part of the law of conservation. I mean hey, all that matter in the universe randomly disappears! That’s obviously not following the law so it’s a moot point in this hypothetical question.

  • If everything blows up, there’s nothing for fields of force to act through or on and thus no energy to potentialize or actualize.
    I am, of course, assuming that fields of force can only become apparent in the presence of mass-energy.
    Occham’s Razor in all things.

  • my theory is Black Hole.
    I’m only 16, so it could (and would) be wrong…

    of 2 things emerge, they will create an implosion. and that will create a black hole.

    pretty simple explained, but it’s a theory.

  • I don’t really know physics, but sice there are no variables acting and the nergy cannot be created nor destroyed this would to htere no being a way to transform energy and energy remaining influctuous.

    To put it simple, potentaial energy will remain “potential”

  • Unfortunately, you can’t just “blow everything up”. All the mass – and more to the point – all the energy that everything is made of, would still be in the universe somewhere, and would still be exerting a gravitational force on the object.

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