Ground Definition and 921 Threads

Homework Statement I'm having trouble with part A of this question 1. A ball is fired out at an angle of 30° from the platform of height h = 0.5 m as shown in Figure 1. It is subjected to the gravitational force only thus follows a projectile motion. It falls onto the ground after 0.6...

A question I have faced in exam to calculate ground state energy Given Hamiltonian 1/2m(px2+py2)+1/4mw2(5x^2+5y^2+6xy) ground state energy has to be obtained Its clear that the Hamiltonian is a 2D LHO Hamiltonian but what for the term 3/4(x+y)2

1. The problem statement Consider a particle of mass m under the action of the one-dimensional harmonic oscillator potential. The Hamiltonian is given by H = \frac{p^2}{2m} + \frac{m \omega ^2 x^2}{2} Knowing that the ground state of the particle at a certain instant is described by the wave...

Homework Statement [/B]Homework EquationsThe Attempt at a Solution The correct option is d because which body will fall first depends on the moment of inertia, the less MOI, the fast the body reaches the ground. COM motion will not be applicable here as the friction force will be different...

Rolls or brake falls slow down how fast your body hits the ground by well rolling.How does this decrease impacted.

This is from *Statistical Physics An Introductory Course* by *Daniel J.Amit* The text is calculating the energy of internal motions of a diatomic molecule. The internal energies of a diatomic molecule, i.e. the vibrational energy and the rotational energy is given by...

This is what I have and I was wondering where C2 might go if I make apply the hybrid pi model on this circuit. I know that all the DC Voltages should be shorted if I were to make use of an equivalent circuit, so that in the hybrid pi model R1 should be in the input and R3 in the output. But what...

Let's say there are two objects. One is thrown directly downward at v0 and the other is thrown horizontally (90 degrees) at v0, both from height h. Which object will have a higher speed by the time they hit the ground? Would they have the same speed? For the object thrown downward... h = (vf2 -...

Suppose I am trying to push a heavy block on ground and I haven't applied a force stronger than the maximum static friction. The force of friction acts on the block and its equal and opposite force acts on the ground. Does the reaction force of friction(acting horizontally on the ground)...

Yeah, the Brits are going to build a car that can potentially hit 1,000 miles an hour. Or a tiny bug and go cartwheeling into the next country. Bloodhound supersonic car fires up Eurofighter engine By Jonathan AmosBBC Science Correspondent The Bloodhound supersonic car has been fired up for...

I've got experience with win32API but its' a pain in the ass. What else is good for cross platform low level programming of apps, want it to work for PC, linux, be able to handle serial data streams, convert data and do C++ tier things. So far been using processing but that's not powerful...

Hi. As far as I know, the main reason for using AC in electric power transmission is that voltage can easily be transformed. If there was a similarly easy way for transforming DC, would power grids work basically the same? To be more specific, how much does AC power transmission rely on the...

Hi I am trying to do a transient heat transfer calculation. The water flowing through the pipe is laminar (1 m/s, id = 0.0127 m, Re_d = 0.01) transferring heat to the pipe via convection, then the pipe (od = 0.015875 m, l = 144 m) transfers heat to the ground again via conduction. I found this...

Homework Statement A ball is thrown straight up from the edge of the roof of a building. A second ball is dropped from the roof 1.00s later. You may ignore air resistance. If the height of the building is 20m, what must the initial speed of the first ball be if both are to hit the ground at the...

Homework Statement Homework EquationsThe Attempt at a Solution I assume that the wheels are 8ft apart in both x and y direction. Let's denote the length and width of the car by 2l = 8 ft. The torque about an axis connected the contact points of rear wheels : ##\vec \tau = [\{l( \hat x +...

Suppose I want to find the ground states corresponding to several Hamiltonian operators ##\left\{ \hat{H}_i \right\}##, which are similar to each other. As an example, let's take the ##\hat{H}_i##:s to be anharmonic oscillator Hamiltonians, written in nondimensional form (##\hbar = m = 1##) as...

I'm building an Arduino voltage logger that includes an op-amp (OP27G) as a buffer on the input. Since I'd like to be able to measure voltages all the way down to zero, I want to power the amp with a bipolar supply. My initial thought was to build the rail-splitter below so I wouldn't have to...

Hi Guys, could someone kindly look at my solutions and let me know if I did everything correctly. Thanks a lot! 1. Homework Statement A sniper fires a bullet at 120 m/s at 30° above the horizontal from the roof top of a 35 m high parking garage. If the bullet strikes the level ground beside...

Homework Statement A 160-kg utility pole extends 12m above the ground. A horizontal force of 250 N acts at its top and the pole is held in the vertical position by a cable, as shown in the figure (I have attached the photo). 1) draw a free-body diagram for the pole 2) Determine the tension...

Yah electrons existing the lowest possible energy state! Now suppose, we throw a beam of light towards a ground state of a atom. I heard/know electrons will take up energy from the photon "hv", and go to the next energy level i.e. excited state. Now my point is, is it only the valance electron...

Hello, Hello, I found this youtube video that I have been trying to figure out how they did for a while. Being the good men of science that you guys are, I figured you might be able to explain how he did this: I tried: Filling the ball with water(which worked at slower speeds) Over inflating...

How exist voltage between hot and ground? How we are connected to ground through wood floor, building when we use tester screwdriver?

I have a question for the community. I am doing a further study and trying to locate any information regarding input impedance of an off center fed dipole at different heights above ground. A simple dipole targets 73.1 ohms for 1 wave length or higher above ground. I am not sure if the same...

I started to ponder following problem. I have a driven, damped oscillator where the mass is free to vibrate in y-direction. If I put a wall or a ground near the mass, the mass touches it if the drive amplitude is larger than the distance to the ground. How does this change the normal dynamics. I...

I've read in the popular media that there is a difference between the two. Is this true, and if so, why?

Hi! 1. Homework Statement From the website http://www1.uprh.edu/rbaretti/MomentumspaceIntegration8feb2010.htm we can see the Fourier transform of the ground state hydrogenic wave function : Φ(p) = ∫ ∫ ∫ exp(-i p r) (Z3/π )1/2 exp(-Zr) sin(θ) dθ dφ r² dr (1.1) After intregation...

I'm trying to understand chapter 19 of these lecture notes. But I have some difficulties with what the author explains: 1) In page 176, under equation 19.3 he says: This is weird. If we are considering a local QFT, then how can he say IR physics can cause non-locality? What is he talking...

Homework Statement Hi everybody! I have a problem related to first-order perturbation theory, and I'm not sure I'm tackling the problem correctly. Here is the problem: Consider a hydrogen atom in an externally applied electric field ##\vec{F}##. Use first-order perturbation theory to find the...

Homework Statement A cantaloupe with a mass of 0.45 kg falls out of a tree house that is 5.4 meters above the ground. It hits a tree branch at a speed of 6.3 m/s. How high is the tree branch from the ground? Homework Equations ## \Delta h = \frac {v_i^2 - v_f^2} {2g} ## The Attempt at...

Homework Statement A hydrogen atom transitions from ni= 5 state down to the ground state. a) What is the energy of photon emitted from the transition of the hydrogen atom? b) What is the ratio of the momentum of the emitted photon to the momentum of an electron which possesses the same kinetic...

Hi. I fear I might not have understood some fundamental concepts about electric power transmission. So we have "neutral" which is brought to Earth potential. Does this mean the electrical circuit from the power plant over highly conductive aluminium cables to my home closes back to the power...

I am currently studying a Foundation Program, which includes chemistry. -I can easily understand the distinguishable characteristics between ground and excited state via writing the electron configuration. -But how can an tom changes from ground to excited state ? And can an atom changes from...

Let's say a switch causes a capacitor to charge and the switch opening causes the capacitor to discharge from its positive plate through a common ground to its negative plate. This common ground is connected to other components, if there is a difference in potential in other components to the...

Im studying a application where multiple 12V input voltage are coming into a circuit board, i was told that optocouplers are use to neutral the potential ground difference of the input 12V from various appliances. can someone explain to me how does the potential ground of each appliances varies...

Homework Statement [/B] "An airplane is flying on a bearing of 340 degrees at 400mph. A wind is blowing at a bearing of 320 degrees at 30mph. Find ground speed and direction of the plane." Homework Equations vx=vcosϕ vy=vsinϕ The Attempt at a Solution [/B] First, my teacher told us to change...

There is this debate in car audio forums of this question whether it is better to connect your amp ground to the frame of the car or the battery.. basically they haven't came to a conclusion so I was curious what you guys think... Basically what I mean is that when you hook up an amp in the...

Homework Statement We put a cyllinder with unknown mass and radius 0.1m which rotates with angular velocity 10 /s around its geometric axis on the horizontal ground. After what time does the cyllinder roll without slipping? Coefficient of friction is 0.1. Homework Equations F=ma M=J ⋅ ∝ The...

This question pertains to the classic ladder-leaning-against frictionless wall scenario. The system is in static equilibrium. The ladder is thin and can be assumed to be made of a homogeneous material so that the center-of-mass lies at the geometric center. The forces in this scenario is...

In ANSI/ ESD S20.20 standard, do you know what "Personnel Ground wrist strap Connection (non- monitored)" test for? Regards, priss

Homework Statement sportsman jumps at 5m/s velocity from 5m cliff to water. at what speed does he reach water? so given answer is 11.1m/s though in this book there are some wrong answers (I did try other equations and I got right answer but I want to know why I can't get it using this one)...

Homework Statement [/B]Homework Equations V= kq/r.[/B]The Attempt at a Solution For 8-8, I do not really know how to approach it. For 8-14 , I think that q2=-q1 and q3=q1+q2. I can now use V=kq/r and then find the equations for r>R3 , r=R3 , R2<r<R3 , r=R2 and R1<r<R2 and then graph...

I was reading Peskin&Schroeder's QFT book, and there was some discussion about how ##\left|0\right>##, the ground state of a free field and ##\left|\Omega \right>##, the ground state of an interacting field differ from each other, and they outlined how the latter can be obtained by propagating...

Homework Statement Using Hund's rules, find the ground state L, S and J of the following atoms: (a) fluorine, (b) magnesium, and (c) titanium. Homework Equations J = L + S The Attempt at a Solution I'm having trouble understanding what L, S and J mean on a basic level. I read the textbook...

From the path integral approach, we know that ## \displaystyle \langle x,t|x_i,0\rangle \propto \int_{\xi(0)=x_i}^{\xi(t_f)=x} D\xi(t) \ e^{iS[\xi]}##. Now, using ## |x,t\rangle=e^{-iHt}|x,0\rangle ##, ## |y\rangle\equiv |y,0\rangle ## and ## \sum_b |\phi_b\rangle\langle \phi_b|=1 ## where ## \{...

so i take that the apple doesn't fall but that the ground acelerates up by relativity this means the Earth inflates at a certain rate thing not noticed for the measure instrument inflates simultaneously but we feel the inertia effects of the ground moving up making things fall and keeping us...

Homework Statement An interaction occurs so that an instantaneous force acts on a particle imparting a momentum ## p_{0} = \hbar k_{0}## to the ground state SHO wave function. Find the probability that the system is still in its ground state. Homework Equations ##\psi _{0} =\left(...

Hello Forum, In DC circuits, I understand that a ground is a point or an entire conductor where the electric potential is set to be V=0 and the potential V at any other point in the circuit is referenced to that. How does the the concept of ground loops work? Why are they not desirable? What...

I saw another post about this but i didn't quite find what i was looking for there so i thought i'd give it a go instead with a thread. Homework Statement Calculate the exact value of the kinetic energy of the hydrogen atom in its ground state. No more information is given, we are referred to...

Why don't the electric generator mount closer to the ground. The advantage I can think is that it is easy to maintain(no need to climb) and reduce weight(reduce tower cost), however the extended shaft will cost more. Does the longer shaft cost out weight the easier maintenance and generator...

Homework Statement Height - 15m Time when ball hits the ground after upward throw 3 s. I have been trying to find intitial speed with these formulas : d=v_initial*t-0.5*g*t^2 and v=v_initial+g*t Please help to understand how to find initial speed and after what time the ball is at 15m height...