Energy Definition and 999 Threads

Writing force equations for block ##m## : $$T-mr\omega^2=m\ddot{r}$$ and for block ##M## : $$Mg-T=M\ddot{r}$$ I think there are mistakes in my equations as they are leading to nowhere and morever i think force methods are really risky in this regard . It would be better to write the total energy...

Does the high temperature increase the kinetic energy of molecules or atoms, or does the high kinetic energy of atoms or molecules increase the temperature ? I'm so curious about this. Which concept is more accurate between the two

I did: Work done by gravity+work done by applied force= KE(final)- KE(initial) Work done by gravity should simply be -mgh =100*5=-500J For work done by applied force we know: W=∫F⋅ds which can also be written as W=∫Fdscos(θ) since F is constant i can take that out W=Fcos(θ)∫ds here since ive...

In QFT the objects of interest are the n point Correlation functions which contain all the information about the theory and can be used to compute any expectation value in principle. However I cant figure out how to compute the vacuum energy from the correlation functions alone and cant find any...

i do know how to do the working but i dont understand the concept stated above...

Imagine an empty void of intergalactic space. In this space there is a cloud of diffuse gas, mostly hydrogen and helium. The gas is non-rotating and very cold just above absolute zero. There is nothing else around this cloud, and so it has a clear center of gravity, and no other objects...

Hello, I have been reading that a coal power plant and a nuclear power plant have similar efficiencies, i.e. ~30%. This 30% refers to the conversion of thermal energy into electricity. For example, for 100 Joule of thermal energy, we only get 30 Joule out of electrical energy. How is that...

Hey all. Quick questions for all you NEs and nuclear lovers out there. I am currently finishing up HS and need to decide a major for college. I am trying to decide between EE and NE, but am strongly considering NE. I have always loved nuclear energy and anything related to nuclear in general...

So I understand that I have to integrate the negative of the force function to get the change in PE. I get -(20x^2 - 2x^3) and when I evaluate it from 0 to 2, I get -64N. But, of course, the change is positive. What am I missing? Thank you.

Hello, this question may seem weird but I really need help on this. To bring the formula for the height h of the triangle above, I have to create a relation between potential and kinetic energies of the black ball with mass m (I can't find any other methods than this). For a sphere falling...

how to calculate the site energy corresponding to monomer with gaussview 6?

See also my LinkedIn page under my name, Dirk Smit. I retired recently from a big energy company where I was the corporate chief scientist. I am now affiliated with Oxford Univ and MIT working on the applied science and engineering of the energy transition in particular the role of the...

$$W = W_{gravity} + W_{friction} + W_{air}$$ Dividing by s: $$F_{total} = mg(sin(\alpha)+\mu cos(\alpha))+0.5×C_{d}A\rho×(v+v_{wind}×sin(\beta))^2$$ Then expressing v for both sections separately: headwind: $$0.5×C_{d}A\rho×v^2+v_{wind}×sin(\beta)×C_{d}A\rho×v+mg(sin(\alpha)+\mu...

I think that the second tippe top will spin on its stem first, and the first tippe top will stop spinning first due to its greater mass and lower angular velocity. Here are my ideas: They are given the same initial energy. By the conservation of energy principle, an object with greater mass...

$$K_i + U_i = K_f + U_f$$ $$K_i = \frac 1 2 m(15)^2$$ $$U_i = 196m$$ $$U_f = 0$$ $$K_f = K_i + U_i - U_f$$ $$=\frac {15^2} 2 m + 196m$$ $$=\frac 1 2(15^2m + 98m)$$ $$=\frac 1 2m(15^2 + 98)$$ $$=\frac 1 2m(323)$$ $$=\frac 1 2m(17.97)^2$$ $$v=17.97 m/s$$ Not seeing where I'm...

Thus $$\Delta K=-\Delta U + W_{nc}$$ $$W_{nc}=\Delta K+\Delta U=\Delta E_m$$ My question is about the following statement The system is closed. ##\Delta E_{system}## does not necessarily have to be zero. Where does (1) come from?

I am trying to wrap my head around something and would be grateful for some insight. Specifically, why the different electric fields along different paths to different areas of an irregularly shaped conductor don't impart different energies to inflowing particles. Say we have a negatively...

Hello everyone, I'm currently working on a physics problem involving the rotation of a 5 kilogram ##M=5## solid sphere subjected to a force of 5 newtons ##F=5##, and I've encountered an inconsistency in my calculations. I'm seeking guidance or insights into where I might have gone wrong. My...

In the images you can see what I did I need someone to check answers and show me how to do C part of question

Where does the original singularity get its energy from?

I've had this question for a while now and I wonder if anyone can make sense of it. It's about two scenarios where the difference between them seems to contradict conservation of energy: Scenario 1: In a vacuum chamber, there is a robotic arm, a box, a lower platform and a higher platform. At...

Sorry for my questions as an amateur interested in physics: If light changes its frequency during a long time of travel in space (vacuum?) for all observers (redshift) and therefore its energy decreases (E=hf), what "entity" absorbs this energy? I suppose the answer will be that the wavelength...

Start by finding the equilibrium position, so we have {4mgx}/{a} = mg giving us x = a/4, therefore the spring's length is 5a/4. Now the loss in EPE (and therefore gain in energy of the particle) between the bottom and the equilibrium position is clearly 4mg((a/4 + d)^2 , and then from the...

Hi PF, long time no see. Hope you are all well. Recently I have come into a mental conundrum of a cosmological physical nature. After doing some napkin calculations about the energy of celestial bodies and transforming them into mass via E=mc^2 I've found that said energy is by no means small...

So first I rewrote H as a matrix: $$ H = \begin{pmatrix} a & b \\ b & c \end{pmatrix} $$ And tried to find the eigenvalues/energies of H, so I solved $$ det (H - \lambda I ) = \begin{vmatrix} a-\lambda & b \\ b & c-\lambda \end{vmatrix} = (a-\lambda)(c-\lambda) - b^2 = ac - a\lambda -...

15- mode a 16- m1 1000. -0.111894 $MAT1 17- 8000. -0.888106...

We connect the charged capacitor to the no-charged capacitor (consider the wires to be ideal R=0), the final energy is less than the initial energy of the system. Where is the lost energy? (see example blew)

I believe that this is due to context of application, but now, I'm starting to doubt myself. For example, a helicopter lifting itself has positive PE change. I really don't intuitively understand how this works. Can someone kindly explain this to me?

Hi. If I drop an inelastic body, its potential energy first gets converted to kinetic, then to deformation energy. We use conservation of energy without taking into account the kinetic energy gain of the earth during the fall. However, at first sight conservation of momentum seems to be...

I've only just clocked this to be the case. I asked chat gpt and the say big bang has a lot of merit apparently

I mean by accelerating electrons and ions for energy levels in atom

In the Jan 6 Economist, there is an article about energy ("Britain needs an unprecedented expansion of the electricity grid") headed by this image. I assume that it is part of a power plant but I can't figure out what all those curved tubes are. First, I thought, maybe heat dissipation but they...

I tried using conservation of energy, and using the equations for circular motion, but I can't seem to find a solution. Any help?

I tried to calculate the energy of an H-Atom with the one electron integrals. I tried to solve them numericaly but it didn‘t worked. Thats why I am hear.

Hello everyone, I am working on this problem and I think I almost solved it, but then I noticed, that I do not know what values I have for dn, n and dθ. Can anyone help me with this?

It is good for the people who wants to know physics and it's beauty

I was initially under the impression that time crystals are in lowest energy state and neither gain or lose energy. But other sources suggested they might require a bump in energy after a while to keep going?

The first equation is when I use forces. The block is in static equilibrium, therefore the spring force should balance the gravitational force. The second equation is when I use energy principles. Energy before compression = Energy at compression. The height before is x * sintheta, and the...

Let's say you've created a very large balloon that doesn't explode in a vacuum and filled it with a gas lighter than air. Next, attach the balloon to a basic electric generator with a very light rope and place the balloon in a vacuum tube. Due to the balloon's weight, it will descend in the...

is it even possible to split pu a proton and how much energy would it take to do that? i heard that it requires so much that it would make new a quark.

Why is (1/2)(mv0)^2 = 1/2(M+m0)gh not a valid equation for conservation of energy? Isn't the energy from when the dart is shot the same as when the two masses move at speed v?

When E=mc^2 is rearranged using the substitution c=1/√ε0μ0 , and making mass the subject we get m=Eε0μ0 This equation basically says that mass is directly proportional to the energy contained in an electromagnetic field. Does it not? Does this equation tell us that mass particles are made up of...

Imagine an object, e.g throwing knife, spins in the air but not forced to rotate about a particular axis, i.e no rod impaling it and forcing it to spin about the rod. Then the axis of rotation converges to it's center of mass (CM) to minimize I. But there's nowhere for it's rotation energy to go...

Suppose in a different star system, a space shuttle sized spacecraft acquired a solar mass energy equivalent amount of kinetic energy, then passed through our solar system. While it was passing through the solar system would the craft’s gravitational effects be more similar to the space shuttle...

That question has been puzzling me recently. But I know there is a simple answer to it.

I've tried to solve this exercise but I haven't used one of the properties of the system (the displacement of the masses) so I don't know if I'm wrong about my procedure. First of all, we (obviously) know that $$ P=P $$ And since we can express the power of a force in two different ways, we...

So if we set the damping constant ##\beta=0## that is if we consider an undamped oscillator the amplitude becomes infinity! What is the physical meaning of this phenomena? As we know energy fed into the system is proportional to ##A^2##. So does this mean that an infinite amount of energy is...

Absolutely no clue on how to even begin this question due to the exceptionally poor quality of our lectures, who has also flatly refused to give out any solutions, which I could have used to understand what is going on. I assume the energy has to be obtained by using the eigenfunction equation...

Hello, I am wondering if anyone can give me a hand. I am looking for a unified expression for energy in rotating systems or wondering if one even exists. Any help or equations you wish to share about the topic would be great. Sorry I am quite new to physics. Thanks

Suppose I have a protein PDB file and want to compute energy using the following formula from the coordinates in that file. How can I do that? Sometimes people suggest using the `CONECT` field for that purpose. However, some PDB files do not have this field. Example: 4OSK.pdb (Crystal...