Potential energy Definition and 1000 Threads

Homework Statement Planet 1 has mass 3M and radius R, while Planet 2 has mass 4Mand radius 2R. They are separated by center-to-center distance 8R. A rock is placed halfway between their centers at point O. It is released from rest. Ignore any motion of the planets. The rock is released from...

Hi, I'm a second year Design Engineering student. This year we're having some basic physics class. We're doing projects on potential energy at this moment. I'm having a problem with the following; The assignment: The teacher assigned us that only 6 Joules of potential energy may be used to...

Homework Statement A small truck is equipped with a rear bumper that has a spring constant of 8 x 10^5 N/m. The bumper can be compressed 15 cm without causing damage to the truck. What is the maximum velocity with which a solid 1000kg car can collide with the bumper without causing damage to...

Imagine a 100N block rising at a constant velocity with a 100N force in the vertical direction pulling it, and 100N of gravity pulling it down. The net force on the block is 0, so work, force time displacement, is also 0. However, the block is rising and clearly gaining gravitational potential...

Homework Statement A moving car has 40,000 J of kinetic energy while moving at a speed of 7.0 m/s. A spring-loaded automobile bumper compresses 0.30 m when the car hits a wall and stops. What can you learn about the bumper’s spring using this information? Answer quantitatively and list the...

Homework Statement A 1kg particle is in a potential given in joules by U(x)=3x2+4x-5, where x is in metres. The particle is initially at position x=1m and moving with velocity v=4m/s in the +x direction. Find the position when the particle first comes to rest. Homework Equations dKe = Kf-Ki...

Homework Statement The potential energy for a mss m = 1.0 kg moving in one dimension is given by U(x) = (2.5J) sin πx. The mass starts at x = 0 with an initial velocity v = 0.71m/s. (The plus sign means the motion is in the positive x-direction.) Describe the subsequent motion of the mass...

There are various different ways to try to add up the effective total mass of a configuration of masses in GR in such a way that it comes out to be equal to the total of the source mass as measured locally minus the gravitational binding energy. One of these is for example the Komar mass, which...

Homework Statement An electron with a speed of 5.0x10^6 m/s is injected into a parallel plate apparatus, in a vacuum, through a hole in the positive plate. The electron collides with the negative plate at 1.0x10^6 m/s. What is the potential difference between the plates? Vi= 5.0x10^6...

Theory and my Understanding: So I understand how the frank condon principle let's us effect electronic transitions instantaneously, since the motion of nuclei (on the timescale of such electronic transitions) is quite slow. Consequently, when a photon of light is absorbed you can have an...

Potential energy is energy contained in certain system, for example in physical body mass in gravitational field of Earth. Potential energy at initial position has value equal to work necessary to move mass from initial position to new position. But also, i read that potential energy can also...

Homework Statement A 20.0 kg cannonball is fired from a cannon with a muzzle speed of 1000 m/s at an angle of 37.0° with the horizontal. A second ball is fired at an angle of 90.0°. (a) Use the isolated system model to find the maximum height reached by each ball. (b) What is the total...

Hi, I wasn't sure if this is more Physics/Astro or chemistry because its actually all 3. i've got some conceptual issues with some tasks at hands, and was wondering if anyone could clear that up for me. (These questions are all regarding molecules) 1) How do you create a potential energy...

Homework Statement Find the energy required to assemble two uniform hollow spheres of charge q between radii a and b with a volume charge density roh-v. The shells are separated by a distance c. *description of picture* - two identical spherical shells with inner radius a and outer radius b...

If two bodies A (m = 1kg) and B (M = 2kg) are at height h from the earth, when they fall and reach the ground A will have KE = 1*gh and B = 2*gh, That means double energy. Is the force FA = m*a that acted on A equal to the force FB = M*a that acted on B since a = 9.8 in both cases? FB should be...

Homework Statement A vertical spring is 10.0 cm long when supporting a 20.0 kg mass, and it is 12.0 cm long when supporting a 32.0 kg mass. Assume the stretch is linear with the load. a) What is the length of the spring with zero load? (0.06666667) b) How much work would be done in...

Homework Statement Given a conservative force, how can we obtain the change in potential energy? Given a potential energy function, how can we determine the associated conservative force? One dimensional.Homework Equations Fx = -du/dx ΔU = -∫ F dx The Attempt at a Solution I know I can...

I'm confused by classic description of work and negative work. If someone pulls (slowly) on a rope to lift a bucket in a well, I understand that the person is doing work on the bucket and gravity is doing negative work on the bucket. So, the net work is zero. But if the net work is zero...

Homework Statement A solid hemisphere with radius b has its flat surface glued to a horizontal table. Another solid hemisphere with radius a rests on top of the hemisphere of radius b so that the curved surfaces in contact. The surfaces of hemispheres are rough, meaning no slipping occurs...

Homework Statement Been stuck on this problem. Any help will be greatly appreciated 1. The (actual) spacecraft Deep Space 1 tested an ion drive engine in which Xenon atoms were accelerated (maximum voltage of 1,300 volts), neutralized and used to provide thrust. The probe carried 74 kg of...

I have been studying the Work and Energy chapter of physics and am currently confused on when to make work equal potential energy and when to make it equal to change in kinetic energy. Some of the problems have the work equal to change in KE and some have it equal to PE. For example, why is...

Homework Statement The potential energy function associated with the force F= 4xyicap + 2x^2jcap is Homework Equations F= -dU/dx The Attempt at a Solution i treid to find the magnitude of force n then put in eq bt failed plese help

Hello, here is the question I have to answer; I am aware that the gravitational energy of one layer of thickness dr is dU=-\frac{GM(r)dm}{r} and that ultimately I will have to integrate this over all radii but I am unclear about the expression for \rho_{center}. The only thing that springs to...

Homework Statement An asteroid of mass m = 2.6 × 10^6 kg approaches the Earth. When it is exactly 3 Earth radii away from the Earth's centre its speed relative to the Earth's centre is u = 8.7 × 10^3 m s–1. The asteroid subsequently falls down to the Earth's surface. You may assume that the...

Homework Statement An asteroid of mass m = 2.6 × 10^6 kg approaches the Earth. When it is exactly 3 Earth radii away from the Earth's centre its speed relative to the Earth's centre is u = 8.7 × 10^3 m s–1. The asteroid subsequently falls down to the Earth's surface. You may assume that the...

Hi. In case potential energy V(x) in one dimensional stationary Shrodinger equation does not have smoothness of C-infinity, I assume that some power n of momentum for an energy eigenstate, <p^n>, diverge. Finite square well potential gives infinite <p^n> for n=6,8,10,.. for example. <p^4> also...

1. A single conservative force acting on a particle within a system varies as = (− Ax + Bx6)ihat N, where A and B are constants, is in Newtons, and x is in meters. (a) Calculate the potential energy function U(x) associated with this force, taking U = 0 at x = 0. (b) Find the change in...

Problem: A conservative force F is acting on a particle that moves vertically. F can be expressed as (3y-6) j head N, y is in m and j head is a unit vector along vertical direction. a) Calculate the potential energy associated with F, with the potential energy set to zero at y=0. b) At what...

Homework Statement Find the energy stored in a solid sphere by integrating ##\frac{\epsilon_0}{2} \int E^2d^3r## given that ##E=k\frac{r^2}{4 \epsilon_0}## for ##0<r\le R## and ##E=k\frac{R^4}{4r^2 \epsilon_0}## for ##r>R## Homework Equations ##U=\frac{\epsilon_0}{2} \int E^2d^3r##The Attempt...

When determining potential energy we have the relationship: PE = V*q = E*q*d But depending on the scenario we can't use them interchangeable right? If you want to calculate the work needed to be done by a particle going from a distance Y to right next to another particle of the same charge...

Homework Statement To explain the forces at work when a marble is released from a height and then eventually comes to rest. We did this experiment where two lengths of hose pipe were taped together. The hosepipe was then bent into a semicircular shape (forming a track) and secured onto a clamp...

Hello my name is Aaron! I am a high school senior from northeastern Kentucky designing a pneumatic system of sorts for a science competition and need some help. I will be building a device that converts gravitational potential energy, from a falling mass, into air pressure (or possibly the...

When we release a suspended object, we recover the potential energy due to gravity as the object travels back through the height raised. When we release an extended spring, we recover the potential energy as the object travels back through the distance stretched. But when we release a rotating...

Homework Statement What does the following equation mean and how is it analogous to the relationship between the electric field and the the electrostatic force? V ( ~r ) = U ( ~r ) / q In general, confused about concepts, meanings and vocabulary. The naming of different terms in this...

I understand the derivation of gravitational potential energy when an object is moved away from Earth but when I try to derive the formula for gpe by considering a test mass moving from infinity to r then I end up with a positive gravitational potential energy. Because integrating F.dr from...

Homework Statement We have an object with much smaller mass than compared to the sun. This object is at rest when released at 1AU from the sun. After a week how far is the mass from the sun. The Attempt at a Solution So I look at the gravitational potential energy and set it equal to...

Hi guys! Thanks for this great forum. I have a question I need explanation about please... I just started 11th grade and it's my first time taking springs. In the book, they said : Ep= 1/2 k x^2 I already understand all the previous laws like [w= -1/2 k (x2^2 _ x1^2)] and know where thay came...

Hi, I have a conceptual question regarding Lagrangian dynamics. It has to do with the potential energy formulation. My instructor today mentioned something in class that does not make much sense to me. Here is he most basic example that illustrates my confusion: Take a simple 1dof...

The basic equation is as follows: U=∑kqiqj/Rj with (i≠j) My question is how is this definition useful? What makes you want to say that is the potential energy of the system? For example, I thought that it is useful because if all particles change in position then you could evaluate that...

A meter scale of mass m initially vertical is displaced at 45 degrees keeping the upper end fixed. . find out the change in potential energy.

In a vacuum under standard gravity, an anchored spherical metal electrode is brought to +1,000,000 volts relative to the distant walls of a much larger chamber. (I'm a new user; hopefully this will display as attachment 1) Therefore, electrons that fall through a small gap in the electrode...

Hi, My first post here, hope it goes well. I wonder if someone of you skilled persons could help me and my friend calculate the energy in a falling tree. I´m no good at maths neither good in english but I will try to explain what I´m after. If you cut down a tree that is 25m heigh and weighs...

is GPE at a point the work we must do against the gravitational force to bring an object from infinity to the point? Or is it the work done by the gravitational force?

This question may sound weird but when we lift an object with a force equal to the weight of the object up to a certain height the Earth is doing negative work on the object as well. So shouldn't the net work be zero?

Hi guys I just want to make sure that my understanding of potential difference is right or wrong I just want someone to tell me whether my understanding is right or wrong. I know that when we move a charge if it's attracted to another charge it gain potential energy and when we leave it it lose...

Good day! I am a beginner in Finite Element Analysis and Structural Mechanics. I have problem in understanding the insight of potential energy approach to derive spring element equations. I have already search for similar post and I found this, and agree with the example raise...

When a rubber band is stretched, or a battery is charged, or two massive objects are separated, the potential energy of all these systems increases in each situation. Now say that any of these systems were suspended in space. If we were to measure the gravitational field of the uncharged...

Homework Statement Imagine a lithium atom where the two electrons in the first orbital are at exact opposite sides of the nucleus and the electron in the second orbital is in line with the other electrons so that the three electrons and the nucleus all lie on a straight line. How much work...

in bringing a test charge (+q ) from a postion to another in an electric field of another charge +Q an external force , F is applied which is just as same as the electric force, F[SIZE="1"](electric) how is this possible? doesnt an unbalanced force be required to...bring about this...

Homework Statement A mass of 3kg is 1m above the floor. the zero of the potential energy is chosen to be on the floor. I understand that the 30j potential energy belongs to both the Earth and the mass, so, why don't i take into account also the distance to the center of the earth? Why don't...