Potential energy Definition and 1000 Threads

In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors.Common types of potential energy include the gravitational potential energy of an object that depends on its mass and its distance from the center of mass of another object, the elastic potential energy of an extended spring, and the electric potential energy of an electric charge in an electric field. The unit for energy in the International System of Units (SI) is the joule, which has the symbol J.
The term potential energy was introduced by the 19th-century Scottish engineer and physicist William Rankine, although it has links to Greek philosopher Aristotle's concept of potentiality. Potential energy is associated with forces that act on a body in a way that the total work done by these forces on the body depends only on the initial and final positions of the body in space. These forces, that are called conservative forces, can be represented at every point in space by vectors expressed as gradients of a certain scalar function called potential.
Since the work of potential forces acting on a body that moves from a start to an end position is determined only by these two positions, and does not depend on the trajectory of the body, there is a function known as potential that can be evaluated at the two positions to determine this work.

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  1. J

    Find the power of a man running (work and potential energy)

    I started of by trying to find the work for I got stuck because I did not know how to solve for the Force. I solved for the distance by doing 3=d/5s which gave me 15m. but then I couldn't figure out where to go next in the problem because I don't know how to solve for (f) so an explanation would...
  2. Krokodrile

    Calculating Kinetic & Potential Energy: Is it Correct?

    In this problem i don't find any way to obtain de kinetic energy in KJ/Kg because when i resolve the kinetic energy formula the result its: 1/2 (1300 kg/s) (9 m/s)^2 = 5850 kg * m/s (i don't obtain m^2/s^2, so KJ/Kg its not possible) In the potential energy (w) part i obtain this: m*g ( i don't...
  3. P

    Potential energy due to an external charge and a grounded sphere

    Let us attempt part C first, which is to find the total energy of the entire system. I can definitely find an expression for the force, as given by Coulomb's Law. However, why should I integrate this force from infinity to d, where d is the distance of the external charge to the centre of the...
  4. L

    How Does Potential Energy Dissipation Affect Temperature in a Metal Cube?

    Earlier today I've attended a physics exam and there is a query I'm not sure about. A metallic cube (specific heat capacity 30 cal/K*Kg ) falls from an height of 50 m on a non-conducting surface, and it stops. After the inelastic collision, what is the temperature of the cube? a_ The...
  5. zonde

    I Interpretation of Potential Energy as Field Property

    I will quote this statement from another thread: In that thread number of other posters seemed to agree with this statement. So I tried to analyze it a bit. For the sake of my questions let's say we limit GR to Schwarzschild spacetime and if there are problems with gravitational potential...
  6. T

    Gravitational Potential Energy on an Incline

    Hi, When regarding Gravitational Potential Energy, I know the formula is U=mgh. However, when the object is on an incline (say at an angle of 52 degrees) would it still be mgh or something else? (This isn't homework I simply was just curious).
  7. J

    What effects does an electric field have on potential energy?

    Like an electric field is applying a sort of force on a particle. I was wondering if this at all impacts the potential energy of a particle. For instance, when the force of gravity does work on an object, its potential energy changes as a consequence. Would it be the same thing here?
  8. PhysicsTest

    What Is the Difference Between Potential and Potential Energy in Electronics?

    I want to know the difference between potential and potential energy. The potential is measured in volts and we provide potential ex 12V to a circuit. Some times we also say a potential energy to be applied to the electron ex. 1eV etc. I know eV is energy, but my question is do we need to...
  9. F

    Internal forces converting kinetic into potential energy (vice versa)

    Hello, Trivial question: a system is isolated and all its internal forces are conservative. Because of Newton's 3rd law, all internal forces are pairwise and the net internal force is always zero (regardless of the forces being conservative or not) hence the system's total momentum is conserved...
  10. J

    Using Orbital Energy to Calculate Velocity

    So what I did first was calculate the initial and final potential energies with Epi=-9.433*10^11 m and Epf = -1.503*10^12 m. Then I found change in potential energy, -5.597*10^11 m. Using this I determined the change in kinetic energy, 5.597*10^11. I then added this change to the initial...
  11. F

    Conservative forces, Nonconservative forces and Potential Energy

    Hello, I would like to review and validate some concepts that I have been recently thinking about. Hope this is correct and useful to others that need to refresh these concepts. Forces can be classified as either conservative or nonconservative. Dissipative forces are always nonconservative...
  12. Andrei0408

    Is d=r=0.5m or d=2r, so r=0.25m for Gravitational Potential Energy?

    I know I just have to replace in the equation, I just want to know, is d=r=0.5 m or is d=2r, so r = 0.25 m ?
  13. M

    Physics C: Mechanics - Negative Energy and Potential Energy Curves

    I'm currently taking a course where we are working to teach older physics concepts and combine them with calculus. I was assigned to work on teaching a unit about energy; for the most part, it stays relatively consistent and can be solved algebraically. Another topic in this unit is Potential...
  14. Adams2020

    Mass difference due to electrical potential energy

    I do not really know the relationship between potential energy and mass difference. Isn't the difference in mass of protons and neutrons due to their quarks? (the neutron is made of two down quarks and an up quark and the proton of two up quarks and a down quark.) Please help.
  15. J

    Gravitational Potential & Gravitational Potential Energy

    Hi, I am confused about the negative aspect of these quantities. The definition in my book for gravitational potential is: "The work done to move a unit mass from infinity to a point in a gravitational field" I understand that the work done is negative because gravity is doing the work if you...
  16. Sj4600

    How Do Electron and Proton Accelerations Compare Between Charged Plates?

    Ve=0m/s Vp= 0m/s Qe/Qp= 1.60E-19 Me=9.11E-31 Mp-1.67E-27 Ive pretty much gathered all of the equations I think I need to solve the problem. I just am stuck. The last step I realize that the forces would be equal to each other so I have mp x ap = me x ae but then when I try to solve for the...
  17. AN630078

    Potential Energy and raising a satellite from Earth into a Circular Orbit

    a. V=-GM/r V=-6.67*10^-11*6.0 x 10^24/6.4 x 10^6 V grav = -62531250 ~ -62.5M Jkg^-1 b. To find the gravitational potential 200 km above the surface of the Earth; r=6.4 x 10^6 +2*10^5 m=6.6*10^6 V grav=-6.67*10^-11*6.0 x 10^24/6.6*10^6 V grav= -60636363 ~ -60.6 M Jkg^-1 Can I check that it is...
  18. Leo Liu

    Definition of potential energy

    Potential energy is generally a function of position vector ##\vec r## and it is defined as ##\int_i^f \vec F(\vec r)d\vec r=-U(\vec r) \bigg| _{i}^{f}=U(\vec r_i)-U(\vec r_f)##, where the force is conservative. Using the fact that the integral of force is also the definition of work, I obtain...
  19. R

    Potential Energy of an Electric Dipole in a Uniform Field

    I have a lot of questions about this single concept. You don't have to answer the questions in the order that I ask, if it is convenient to answer them in a different order. 1. When the dipole moment ##\vec{p}## is in the same direction as the electric field (uniform) it has the least potential...
  20. plomeiko

    Question about gravitational potential energy and angular motion

    hello I would like some help with the first part of this homework. for the moment i have done this: E initial=m*g*h Efinal= 1/2 m*v ^ 2+1/2I*ω ^ 2 Ei=m*g*h+1/2I*ω ^ 2 Ef=1/2*m*v ^ 2 my doubt is with the potential energy since it confuses me when there is or not...
  21. Hamiltonian

    Work done by a conservative force using change in potential energy

    we know ##W_g = -\Delta U## but here to find ##\Delta U## we will need another equation won't it be wrong to write $$-\Delta U = -\int_1^{0.8}mgdy$$ as this equation is derived from ##W_g = -\Delta U## and as we have 2 unknowns we will need two equations. this is a rather easy problem but I am...
  22. snoopies622

    B Does E=mc^2 apply to gravitational potential energy?

    I'm reading Schutz's A First Course In General Relativity and in chapter 5 he discusses an idealized experiment in which an object is dropped from a tower, then turned into a photon and sent back up to its original height. In classical mechanics we would say that as the object falls it loses...
  23. cwill53

    Solving for Electrical Potential Energy: Durcell's Example

    This question is an example in Durcell's Electricity and Magnetism. The solution goes as follows: [In this case] there are four different types of pairs. One type involves the center charge, while the other three involve the various edges and diagonals of the cube. Summing over all pairs yields...
  24. Hamiltonian

    Gravitational potential energy -- Why is it always negative?

    the gravitational potential energy of a body at any point is defined to be negative of the work done by the conservative force(gravity in this case) from bringing it to that point from a given reference point. if the reference point is taken to be at infinity and the potential energy at this...
  25. G

    How Do Kinetic and Potential Energy Differ in Physics?

    I know that (1/2)m(u^2) is KE and initially I thought this showed PE=KE but I don't think so anymore... I believe this has something to do with acceleration and Centripetal force but I'm so so confused
  26. Sagittarius A-Star

    B Potential Energy formula in Special Relativty

    Reference frame is an accelerated frame in SR (uniformly accelerated with "g" in flat spacetime). An object is falling with relativitic velocity of up to 0.8 c in the pseudo-gravitational field in this frame. From Newton's theory, I know the formula for potential energy in such a scenario: ##W...
  27. K

    What is the origin of magnetic potential energy?

    Recently I have encountered the following expression for the potential energy of a magnetic dipole of moment ##\boldsymbol{\mu}## placed in an external magnetostatic field B: $$U=-\boldsymbol{\mu} \cdot \textbf{B}$$. However, I was told that magnetic fields are non-conservative, so we can't...
  28. rufusbufus

    Calculating the energy created by a bike pump that feeds a turbine

    Summary:: I have an assignment that is looking at how a bicycle pump is used to push air through a turbine to generate energy. I need to determine the energy input and energy created. I'm hoping I can get some direction on where to start. The concept is straightforward. A bicycle pump of...
  29. marialovesphysics

    Gravitational potential energy formulas

    m.g.h = (GMm)/r how can we prove that mgh is potential energy and both equal to that?
  30. L

    Calculating the elastic potential energy from a force-extension investigation

    1. The student should use a rubber band, g-clamp, a retort stand, boss and clamp, a mass hanger, 100g masses and a metre rule. The rubber band should be positioned to hang freely from the retort stand, held in place by a g-clamp to the laboratory bench. Measure the length of the rubber band...
  31. iochoa2016

    Understanding Electrical Potential Energy of a charge distribution

    I quite understand the fact the EPE (Electrical Potential Energy) of a system of two charges are U = k*qQ/r, Q is fix. however when it comes to three charges i get lost. because my reasoning is : if q1 is fix then the EPE of the system when q2 is brought is U2 = k*q1*q2/r12, when q3 is brought...
  32. Frigus

    Why the change in potential energy is the same in all cases?

    Definition of conservative field I use:-it is a field in which potential energy of system is independent of path taken. I understand that it is independent because whenever we take some path than all the perpendicular displacements with respect to force are not counted and if we go further than...
  33. R

    Why gravitational potential energy is a system property?

    Spring has more potential energy when it is compressed or stretched from its initially balanced state. As external work is done, it stores energy in the form of potential energy. Here, we know energy is stored in spring but For the Earth-ball system, where the energy stored?
  34. E

    A general potential energy for a multi-particle system

    For a system of two or more particles, it is customary to define potential energy functions ##V_{ij}## between pairs of particles, so that the total conservative force (not necessarily total) on any given particle is $$\mathbf{F}_i = \sum_{j\neq i} -\nabla_i V_{ij}$$as a sum over all other...
  35. apathetic_operator

    What does a force of zero indicate about the total force acting on a particle?

    "The force is zero" means the total force act on the particle is zero? Then there must be an external force. If not, then Fx=0 ? since Fx = d(U(x))/dx, the answer of (b) should be (i), but how about (a)?
  36. P

    Case when the potential energy of the 1st excited state is zero

    I know how to solve this problem when the energy at ground state is zero but I don't know how to deal with 1st excited state energy as zero. According to me since the potential energy is zero therefore the kinetic energy must be 13.6eV according to conservation of energy. I also know that the...
  37. LCSphysicist

    Question about potential energy as a mass approaches infinity

    I was thinking, what would be the consequence if we wouldn't adopt the ro in the infinite, and i conclude that it would just irritate the accounts, with one constant more, am i right? Once what matter is the diference between the U, and no the U infact.
  38. A

    Potential energy of a system of two punctual charges along the X axis

    I have not clear how to solve this problem. Here it is my attempt at a solution: Let the charge at ##-a## be the number one and the one at ##+a## the number two. the potential energy of the punctual charge ##-Q## due to each charge +Q will be then ##E_{pi}=-k \frac{Q^2}{r_i}##, whit ##r_i## the...
  39. A

    Negative potential energy and capacitors

    https://www.mytutor.co.uk/answers/11559/A-Level/Physics/What-is-gravitational-potential-energy-Why-is-it-negative/ But a parallel plate capacitor is oppositely charged, so the plates attract. With the same logic don't they store negative energy and wouldn't you get the wrong answer from a...
  40. P

    Potential energy of a System of charges

    This is my attempt the system The 1 is the initial configuration where the 3 electron is at infinity. The 2 is the final configuration where the 3 electron is midway.U1 is the potential energy between e1 and e2 U1 = (q1*q2)/(4*π*ε0 * (0.02)^2); // q1, q2 charge of electrons K1 =...
  41. I

    Physics momentum problem -- Collision between 2 blocks that stick together

    So far I found the answer for a and b, but when I attempted to do the other ones I was completely lost. A.) P= MV M = 25g = .025kg V = 18 .025 * 18 = .45kg*m/s B.) KE= 1/2 mv^2 1/2 (.025)(18)^2 4.05 J
  42. T

    Electrical potential energy questions for a battery circuit

    I’m trying to learn about simple circuits but I have a few questions because I don’t fully understand what’s going on . 1. If the reason current flows when a wire is connected to the ends of a battery is due to a potential difference across a battery , why can’t the current just flow through...
  43. Tony Hau

    Potential energy as a function of the square of this angle

    The problem of my question is the b part below: I know that the potential energy is just the gravitational potential energy, which is mgh(𝜃) = mg[(R+b/2)cos𝜃 +R𝜃sin𝜃], derived from the geometry. The equilibrium point is at 𝜃=0 and the system is a stable equilibrium for R>b/2. However, I have no...
  44. GhostLoveScore

    Finding the potential energy of a time dependent force

    U=-∫F*v*dt= -∫(m*g/3)*cos(ω*t) dt = -(m*g/3 )* (v/ω )* sin(ω*t) except that according to the official solution, I should be getting positive sign instead of negative. Am I doing something wrong?
  45. E

    Meaning of potential energy in external fields

    Generally potential energies are associated with a system of two bodies. If more than two bodies are involved the total can be determined by summing the contributions pairwise. It would appear as though in any system, the potential energies are all internal to the system. However in classical...
  46. E

    Clarification of (misleading?) potential energy diagram

    I've seen this figure kicking around, and just wanted to check that I'm not going mad. ##r_{0}## is supposed to be the Bohr radius of the first electron. I don't think this is quite right, since at ##r_{0}## the potential energy is about ##-27eV## or something, so I think they've actually...
  47. E

    Potential energy of a dipole in an external field

    I'm considering the arrangement shown below. Let the positive charge be ##q##, and the negative be ##-q##. To derive the potential energy of this configuration, one usually adds the potential energies of both of the charges in the external field, taking the zero volts equipotential of the...
  48. Blakely42

    Potential Energy vs x phase diagram

    U(x) = - ∫Fdx = - (1/2)kx^2. T = (1/2)m(x')^2. E = (1/2)[m(x')^2 - kx^2]. We could write out the Lagrangian here, but the chapter this comes from (Taylor's Classical Mechanics 13.6) indicates we should probably write the Hamiltonian, H = T + U. As far as I can tell, this doesn't tell me a...
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