Energy Definition and 999 Threads

The answer in the textbook says 0J but I am not sure what the concept behind it is. Does it have something to do with gravity?

Homework Statement:: Ionised atom, free electron, conduction band, donor energy level and acceptor energy level Relevant Equations:: None I have some confusion about the concept of some electronic bands and energy levels. Beyond valance band, in a solid crystal lattice, For an atom, can...

If I have a force that behaves according to the formula ##F(x)=\alpha x-\beta x^3##, how can I get the potential energy from it? I know that: $$-\frac{\mathrm{d}V(x)}{\mathrm{d}x}=F(x),$$ but what about the limits of the integration?

hi guys I am trying to derive the Gibbs free energy for a superconductor in the intermediate state , the book(Introduction to Superconductivity by A.C. Rose-Innes) just stated the equation as its : $$ G(Ha) = Vgs(0)+\frac{V\mu_{o}H_{c}}{2n}[H_{a}(2-\frac{H_{a}}{H_{c}})-H_{c}(1-n))] $$ I am not...

I want to do RF energy harvesting simulation for the measurement of Power Conversion Efficiency. So how can be simulation done on a single platform?. Kindly suggest

So, the Cp and Cv its very confusing for me. But, i understand what's its happening in this process, so, i use the logic and first i obtain a ecuation for obtain the final temperature ecuaticon: Q=m*C*△T Q=m*C*(T2-T1) T2=(Q+T1)/(m*C) If the process its in constant pressure, i use the Cp valor...

How to demonstrate that about 25% of the radiant energy in a cavity is concentrated between 0 and maximum energy wavelength?

-

A few days ago a new dark energy map was published, which some claim "strays from Einstein's theory of relativity". To quote from the BBC News website: "Dr Niall Jeffrey, of École Normale Supérieure, in Paris, who pieced the map together, said that the result posed a "real problem" for...

I'm given an ultra-high energy cosmic ray with energy 10^20 eV. It is coming from a source 10 Mpc away with an extragalactic magnetic field with strength B = 10^-9 G. I am to determine the maximum angular deflection of this cosmic ray, so it hits Earth. I don't have an attempt of the solution...

The mass (rest mass) of an atom, for example, depends on the kinetic and potential energy of the particles and their individual masses. Kinetic and potential energy are relative. Why is the mass not relative, but the same for all reference frames?

If we look at system at constant temperature and volume which is galvanic cell, first law of thermodynamics states: $$ dU = dQ + dW' $$ Where W' is electrical work done by galvanic cell and Q is heat exchanged with surroundings. As far as I know electrical work is work done by electric field...

I almost always buy food from local market but recently I want to buy some rice (and probably other foods later) overseas which will be imported through our customs, so most likely the food will be scanned through x-ray or other high energy devices that I don't know, could rice grains or other...

Hi everyone, In my physics class, we are doing the Hollywood Physics Project. It's a project where you analyze the physics from a scene in a movie and talk about if it's accurate or not. I chose the scene from the Avengers where Thor strikes Captain America's shield with his hammer. The...

Why is the energy of a circuit placed in a magnetic field at infinity zero?

So far, I have found g of the foreign planet, Vf of the ball, and realize that GPEiA = KEfA (Am I right here?). Thus, since GPEiA = GPEiE, GPEiE also equals KEfE. I also understand that, since the same impulse is applied to catch the objects, both objects have the same momentum at the moment...

Answer: a) 7.35 m/s b) 216.09 m/s^2 *Is this correct?

Hi, I was reading the following article. Source: https://www.forbes.com/sites/startswithabang/2019/01/31/dark-energy-may-not-be-a-constant-which-would-lead-to-a-revolution-in-physics How come the density of dark energy remains constant? Yes, if it's intrinsic to the space itself and more...

Hi, If we are standing on the ground, the Earth applies a force equal to our weight to us, but why do we feel a greater force when we fall to the ground from a certain height? Our weight is the same along this small height because our mass and acceleration are the same and, even so, the normal...

Hi, I've a doubt about how to the energy is stored in a 'real' RLC parallel resonant network feeds from a sinusoidal source. Take a 'real' RLC parallel network having a resistor ##R_s## in series with the inductor ##L_s## (modeling its loss) with the capacitor C in parallel and consider it in...

How exactly would it then be calculated? Here's what I have tried: proton mass: 1.007276 amu Neutron mass: 1.008665 amu Sulphur-34 mass: 33.9678668 amu Calculation: 1.##(16\cdot1.007276)+(18\cdot1.008665)+(16 \cdot0.000549)=34.28117## 2.##34.28117-33.9678668=0.3133032## 3. 1 atomic mass...

I'm looking to find formulas to calculate the energy stored in a spring you would find in a clock. I have been having a hard time finding formulas that govern these types of springs. I have found formula in similar springs, such as the spiral-torsion spring found here but I believe this type...

The current density between the plates is J = 1 A/m2. So, I have to calculate first the magnetic energy in the whole space. Out of the sheets, there is no current, so the magnetic energy would be 0 in that places. Hence, U = J(1/2) \int_{inside the plates}A(r)dr, where A(r) is the vector...

The question is below. I tried reasoning that because x is constant, E is also constant however that gives me values in the range of 10^51. Then I tried to use numpy's ivp_solve function to solve the differential equation however I wasn't able to get that working either. Apparently I'm meant to...

Hello Gents, I am very confused about the working principle of gas turbines. I understand that air is first compressed in a compressor to obtain high pressure air at the inlet of turbine, but before air is introduced to the turbine, first it has to be heated to very high temperatures through...

Good day, If I consider my system to be an object and the earth, and the object is on the surface of the earth, then the system will have gravitational potential energy. Why couldn't I say that only the object (considering it as my system) has gravitational potential energy? Thanks

Guys, I have a problem that really needs you guys to help, I know it is a stupid question but please bear with me: Context: You have a block on a slope(has friction) you use a string to pull the block up with constant speed. Problem: So according to the network theorem, the work net is equal...

Hi all. I'm trying to prove energy conservation in a (maybe) uncommon way. I know there are different ways to do this, but it is asked me to prove it this way and I'm stucked at the end of the proof. I'm considering ##N## bodies moving in a gravitational potential, such that the energy is ##E =...

I am a student at high school who just finished a paper about nuclear energy and I really learned a lot from it. I found the topic interesting and really enjoyed learning about it. I now am searching out more people who know about it and as much information as I can fins while having good...

Inertia I = 2/5 mr² m=5.98* 10^24 kg. r=6.38* 10^6 kg. I= 9,736 * 10^37 kg. Earth rotation is V= (2 * pi* R)/T = (2*pi*6.38*10^6m)/(24*3600s)=463 m/s angular velocity w= V/r =463m/s/(6.38*10^6m)=7.27*10^-5 rad/s Enerrgy, E= 0.5* I*w²=2.57*10^29 j I get the...

In a globally hyperbolic spacetime you have a global time ##t: M \longrightarrow \mathbf{R}## which foliates it into Cauchy surfaces ##\Sigma_t## and the metric can be written ##\mathrm{d}s^2 = -N^2 \mathrm{d}t^2 + h_{ij}(\mathrm{d}x^i + N^i \mathrm{d}t)(\mathrm{d}x^j + N^j \mathrm{d}t)##. By...

Hi guys, a special relativity problem requested to choose the right graph representing relativistic momentum ##p## as a function of rel. kinetic energy ##K##, from these four: At first, I tried writing ##p## as a function of ##K##, in order to then analyze the function's graph and see if it...

Hello everyone, I am sorry if this question looks silly but my tutor has not replied yet and I need to work it out as soon as I can. Could someone tell me if they see any difference question 1 and question 2? Because I genuinely don't and it is driving me crazy. The assignment is about a coal...

As we know Energy is a scalar quantity. So when we add kinetic and potential energy to get Total energy. So addicting these two energy (kinetic and potential) comes under Scalar addition ? I just wanted to confirm it.

I have no idea how to do this. I've tried conservation of mechanical energy and it didn't work. Ek = Kinetic Energy R = horizontal range of the ball h = height from which the ball is released

So it seems the typical way to approach this problem is to consider the sphere when it has charge q and radius r. With uniform charge density ##\rho##, this becomes ##q = 4/3 \pi r^3 \rho## and so ##dq = 4 \pi r^2 dr \rho##. Using our expression for the potential outside of the sphere, we find...

We have a question about highly energized beta particles (6 to 22 MeV). Is it possible fore this radiation to affect the nucleus of an isotope and not just ionize it? In our case a copper-65 and copper- 63 isotope become their unstable neighbors Cu-64 and Cu-62 due to the high beta radiation...

VR = IR = 400 [ 29*10^-6 * 800 * 10^3 ] = 9280 P = IV = 400*9280 = 3.7 MW I was able to calculate the correct answer from the above, but why can't I use the equation P= V^2 / R?

In an article published in Scientific American, authors Adam Riess and Mario Livio wrote: Why negative pressure? I would think the pressure would be positive, thus making gravity repulsive.

I had found what U(x) was equal to already by plugging in the wave function and simplifying, which is (2h^2/mL^4)(x^2 - 3L^2/2) by the way. But the solution key that I have goes an extra step. After stating the equation of U(x) that I got, it says that: "U(x) is a parabola centred at x = 0 with...

D is correct, the reasoning is as follows: 1/2*(M1V1)^2 + 1/2*(M2V2)^2 = 1/2 * (M1 + M2) (Vcm)^2, since V1 =V2 =Vcm KE retained = KE final = 1/2 *M(Vcm)^2 Let me know if reasoning is okay? However, why A isn't correct?

I am trying to understand the scalar form of the Einstein field equations. I know that you can contract the stress-energy tensor using the metric. And for a perfect fluid model, this turns out to be the energy density summed with the pressure. This also gives the Ricci scalar. However, you can...

So always in my problems i had mass (M) but now i don't and it seems impossible to solve this problem if I don't have mass I think i am missing something. I was looking for similar problems in my book and internet and didn't find any.

Can energy be defined as an entity? The ability to do work is abstract, so is E=mc^2. It seems like energy is a catch-all phrase for something we can only describe in terms of other physical realities.

Energy is equal to Planck’s constant times the number of waves in 1 sec. The time scale for electronic excitation is far shorter then one second. So when we talk about the excitation of an electron from a lower level to a higher level occurring at a certain energy, are we talking about the...

Hello guys, I am designing a 1052 kwh solar farm with 2844 panels in Wales. These panels have to supply energy to a train station but I get minors coverage of the energy required if I do the following calculation which is based on the average sunshine of hours per month. What do you think about...

Hello everyone, I have found this on internet but I don't get the calculations. Can someone do the calculations and show me that the annual consumption is 600 kWh is you use a 200 Wh computer for 8 hours?: A complete desktop uses an average of 200 Watt hours (Wh). This is the sum of the average...