Potential energy Definition and 1000 Threads

1. I have two blocks, one that is 1.6 kg moving left at 3.00 m/s and the other is 2.1 kg moving right at -1.74 m/s, and they are compressing a block with a spring constant of k=600 N/m. I'm supposed to be finding the distance that the spring is compressed at that instant, and I know that...

Homework Statement The mechanism in the attached photo contains two masses, each treated as particles. When released from rest, the 4-kg block falls and the 6-kg sphere rises. Initially, the angle between the two rigid, massless linkages is θ = 60° What is the velocity of the sphere when θ =...

Matter can neither be created nor destroyed...but potential energy can be converted into a different kind of energy. Let's say we have a spring with a mass connected to it. This mass is a magnet, and the apparatus is inside a copper coil. It's a horizontal magnet with friction minimized at the...

Homework Statement Figure 8-36 shows an 8.00 kg stone at rest on a spring. The spring is compressed 10.0 cm by the stone. (a) What is the spring constant? 2. Relevant formula Mechanical energy is conserved The Attempt at a Solution The decrease in gravitational potential energy that occurs...

Suppose we have two boxes, A and B with different masses, the spring is fixed to block A. Then we take block B and press it against block A so that the spring compresses. Afterwards, we let go of both boxes. If we were to model this using the conservation of energy, then it is known that...

Homework Statement I am currently learning about elastic potential energy and this is a question that was given to us by my teacher: When a 13.2-kg mass is placed on top of a vertical spring, the spring compresses 5.93 cm. Find the force constant of the spring. Homework EquationsThe Attempt...

Homework Statement Two Charged Objects (Q1= -9.0nC & Q2= 15nC) are fixed in place on the +x-axis. The first charge is 12 cm to the left from the origin the other is 12 cm to the right from the origin. A proton is moved from the origin to a position on the +y-axis 9.0 cm from the origin. a)...

About the formula deltaPE=-qE(deltaX) .. Whats the negative sign means ?

Why is gravitational potential energy directly related to the distance of between two objects (mgh, so as distance increases, potential energy increases) while electric potential energy is inversely related (kq1q2/r,distance increases, electric potential energy decreases)?

Homework Statement A uniform electric field of 16.9 N/C is directed in the positive x direction. If a charge of -2 micro-coulombs moves 2.2 meters in the negative x direction, how much does the electric potential energy change in micro-joules? Homework Equations ΔEPE = qEd The Attempt at a...

Homework Statement In the pictures. Homework Equations KE = 1/2mv^2. PE = 1/2kx^2 Work external = Delta KE + Delta PE W = F* dThe Attempt at a Solution In the pictures.Comments: On Problem 3 ai, I am not sure whether I have identified the correct horizontal forces. The hint gave two, but I...

1. With respect to any oscillating system, what is the difference between ΔPE, PE, and PEaverage?Homework Equations ---- The Attempt at a Solution Hi all. I want to preface this by saying that we have been discussing the Lennard-Jones potential and particle theory in class recently, after...

Hi there, I'm trying to brush up on some of my E&M and am comparing treatments of Coulomb's Law in introductory calculus-based texts with higher level material. My understanding was that Coulomb's Law (and by extension, calculation of the electrostatic force on a charged particle using F = qE)...

Homework Statement The net force on the mass is the central force F(r) = -k(r-a). Find the potential energy U(r). a is the spring of natural length and k is spring constant k. Homework Equations -dU/dx = F(x) The Attempt at a Solution F(r) = - \frac{ dU }{ dr } implies -k(r-a) = - \frac{ dU...

I have a .81 Cu. Ft. cylinder which is at a static pressure of 80 Psi. What is the easiest way to calculate the Potential Energy of the compressed air?

Homework Statement What is the potential energy of the system composed of the three charges q1, q3, and q4, when q1 is at point R? Define the potential energy to be zero at infinity. Charges are arranged in a triangle, with q3 and q4 located up and down 2.2 cm from the origin, and q1 on the...

Hi, I am confused over the potential energy equation. I have been taught that potential energy is MGH M=mass, G=gravity on surface, and H=height from earth. However being on the internet and learning more i have noticed people use GmM/r^2 and i am very confused why it is switched. please help me...

I am from New York, and a physics student. ( not trying to give to much info on the internet.) but i was curious in why people on the internet use PE equation as GmM/r^2 when i was taught that it was PE=MGH? please help me with me confusion? thank you.

(constants're ommitted) 1-) M=50, m=5, h=5 then Potential Energy = (50*5)/5 = 50 After increasing height 2-) M=50, m=5, h=10 then Potential Energy = (50*5)/10 = 25 Field strength decreases amount of h^2 so according to formulas potential energy decreases as h increases. But that mustn't be...

Hi guys, So I'm trying to understand why the potential energy of a Lagrangian is the way it is. The system I'm considering is a closed necklace of N beads, each of mass m. Each bead interacts only with its nearest neighbour. First let me make some comments: 1) Each bead is labeled with a...

Homework Statement Part A: Derive an expression for the energy needed to launch an object from the surface of Earth to a height h above the surface. Part B: Ignoring Earth's rotation, how much energy is needed to get the same object into orbit at height h? Express your answer in terms of...

Homework Statement Two charges q = 9.0μ C are fixed in space a distance d = 1.5 cm apart, as shown in the figure. a) With V = 0 at infinity, what is the electric potential at point C? b) You bring a third charge q = 9.0μC from infinity to C. How much work must you do? c) What is the...

I read somewhere online that according to Coulomb's law, in the context of an atom, the potential energy of an electron is proportional to the distance (squared) between the positive and negative charges, this however doesn't show up in the actual eq F = kq1q2/r^2 I thought about it in terms of...

Homework Statement Find the Electrostatic potential energy of a cubical configuration of point charges as shown in the figure. Each of the charges is 5.00e and the edge of the cube is 2 cm. (The image is simply a cube with one of the points labeled q) Homework Equations U=kQq/r The Attempt at...

Homework Statement "In order to launch a space probe out of the solar system, it is decided to send it close to Jupiter. Why does this reduce the amount of fuel needed?" Homework EquationsThe Attempt at a Solution I can't think of anything at all. I am trying to think in terms of it gaining...

When we discuss higgs potential energy in textbook, we mean it takes the form ## V(h)= m^2 h^2 + \lambda h^4/4##. My question is: is potential energy always defined at some specific energy scale? since the parameters depend on energy. For instance, if I am interested in the form of higgs...

Effective potential energy is defined by U^*(\rho)=\frac{L^2}{2m\rho^2}+U(\rho) in many problems I found that particle will have stable circular orbit if U^*(\rho) has minimum. 1. Why is that a case? Why circle? Why not ellipse for example? 2. Is this condition equivalent with...

Homework Statement A broken spaceship is located h=10 km above the center of a large circular thin sheet of unknown dust. The sheet has a radius of R=106 km and a density of σ = 7*1011 kg/m2. The spaceship and the dust attract each other due to the gravitational force. a) Find the initial...

In this case the height of the fall is far to high above Earth to be use PE=mgh. So I'm trying to integrate the inverse square gravitational force over distance. ##\int \frac{GmM_e}{r^2}dr## So I'm confused with respect to another object, specifically the moon, if the max height of the fall...

Is less work done in rolling the stone than lifting it? I think so that as gravity is conservative field therefore work done should be equal. But rolling could mean rotational kinetic energy so please clarify this?

I was thinking about the concept of the ground being the arbitrary zero potential point for gravitational potential energy and considered that since gravity is the attractive force between two objects that there would be no potential energy if an object's center of mass were somehow situated...

Given two point masses, ##m_1## and ##m_2##, we define the gravitational potential energy of this system as: $$U_{grav} = -G \frac{m_1m_2}{r}$$ Where ##r## is the separation between ##m_1## and ##m_2##. When we analyze the motion of a single component, say ##m_1## in this system, we usually...

I understand that GPE is negative, but it does not come out this way when i try to derive it. I took the change in potential energy in bringing a particle from an infinite distance to a distance of b from another particle. ## \Delta U = - \int \vec F \cdot d \vec r ##. Since the...

Hello, I am calculating the potential energy surface of an iron slab, once with a ferro magnetic behavior and later anti ferromagnetic behavior, I know for ferromagnetic I multiply the number of atoms by its magnetic moment (I use 3 that must be a little higher than its real value), my...

Homework Statement The problem is to show that the potential energy of a dipole (whether electric or magnetic) is given by ##U = -\vec{m}\cdot\vec{B}## in the magnetic case and ##U = -\vec{p}\cdot\vec{E}## in the electric case assuming the respective magnitudes of the dipole moment remain...

Homework Statement how to prove the potential energy principle? how do you make sense of the potential energy principle ie -dU/dX = F(x). What does the principle really mean? Homework Equations -dU/dX = F(x) where U is the potential energy and F the force. The Attempt at a Solution Not...

Hi, I'm studying the Lagrangian and its applications in electromagnetism. I stumbled across this inconsistency: The force of a charge moving through a magnetic field is ## F_b = q v \times B ## If we define B to be in the ## \hat{z} ## direction, this equation can be written as ## F_b = q (...

.(1)Electron's potential energy decreases when it moves from lower to higher potential,right?And i also want to verify few more things on which i am doubtful .(2)Why when electron passes through resistance it's potential energy decreases?I think because it require energy to pass or cross...

Three charged objects, (+4 micro coulomb, -4 micro coulomb and +2 micro coulomb) are placed at the corners of an equilateral triangle with side length 2m. Calculate the total electric potential energy of the system... Guys Can you help me achieve a solution to this question? Thanks In Advance!

Guys, i really need help on answering this question... Can a charged particle ever move from a low electric potential to a high electric potential and yet have its electric potential energy decrease? Explain. What i think is that, no it is not possible for a charged particle to move to a...

Homework Statement A cylinder with mass M and radius R and moment of inertia I is standing on a rough surface (the left part of the triangle). A box with mass m is standing on a smooth surface (right part of the triangle). The cylinger and box is connected by a massless rope over a massless...

Homework Statement The potential energy function of a particle of mass m is V(x) = cx/(x2+a2), where c and a are positive constants. Qualitatively sketch V as a function of x. Find two equilibrium points: identify which is a position of stable equilibrium, and find the period of small...

Homework Statement Three particles of mass all = 3 kg are located at the vertices of an equilateral triangle and are spinning about their center of mass in an empty space. The sides are length d = 2 m which doesn't change with time. Homework Equations What is the PE of the system? What is the...

Homework Statement Let EPE be change in electric potential energy so if a positive charge is moving towards the negative terminal with the electric field it would mean that it is losing PE therefore work = - EPE, and if a negative charge is moving against the electric field towards the...

Homework Statement I was watching a Khan Academy video (here) on electric potential energy (not Voltage.) Here was the problem: There is an infinitely extending positively charged plane (uniform.) The charged plane has a positive electric field with 5 N/C (Newtons per Coulomb.) Electric...

Homework Statement Forty 2.0kg blocks 20.0cm thick are used to make a retaining wall in the backyard. Each row of the wall will contain 10 blocks. You may assume that the first block is placed at the reference level. How much gravitational potential energy is stored in the wall when the blocks...

Homework Statement A capacitor of capacity C is charged with potential difference V. Another capacitor of capacity 2C is charged to 4V.they are connected with reverse polarity after removing batteries. The heat produced during redistribution of charges is... Homework Equations ##Q = CV## ##U...

1. Homework Statement Two electrons start at rest with a separation of 5.0*10-12m. Once released, the electrons accelerate away from each other. Calculate the speed of each electron when they are a very large distance apart. Homework Equations ΔEK+ΔEE=0 The Attempt at a Solution Okay so I...

Homework Statement A potential energy function for a two-dimensional force is of the form U = 3x3 * y - 7x. Find the force that acts at the point (x, y).[/B] Homework Equations In a 1-dimensional case: ΔU = -∫Fx dx dU = -Fx dx Fx = -dU/dx The Attempt at a Solution I know how to find the...

Homework Statement A simple pendulum of length ##b## and bob with mass ##m## is attached to a massless support moving vertically upward with constant acceleration ##a##. Determine (a) the equations of motion and (b) the period for small oscillations. 2. Formulas ##U = mgh## ##T = (1/2)mv^2...