Ground Definition and 921 Threads

Hi all, this is my first post on Physics forums so I apologise in advance if I have posted in the wrong section etc. This is something that I have been trying to figure out for nearly a week now! I have modeled a vehicle in Solidworks, specifically an external roll cage, and hope to conduct a...

Homework Statement A ladybug with a velocity of 10 mm/s [W] crawls on a chair that is being pulled with a velocity of 40 mm/s [40 degrees N of W]. What is the velocity of the ladybug relative to the ground? Homework Equations The Attempt at a Solution finding the y-component...

Homework Statement For potassium in ground state configuration (Z=19) how would you expect the energy of the least tightly bound electron to compare with the energy of the electron in hydrogen excited to a state of the same principal quantum number n. Explain your answer. Homework...

I have a device in a DC circuit that calls for decoupling capacitors on VIN and VOUT. The circuit is powered by two batteries in series. The above device is hooked up in parallel to the second battery with the device ground connected to the node shared between the two batteries like so...

Ok, so I've been wrestling with the concept of ground for the past two weeks. I'm in an electrical engineering program at college, and let me preface this by saying I have no difficulty dealing with ground in a practical sense and understand its general function very well. That being said, I've...

The "stand your ground" laws Considering the current controversy in Florida over the death of a minor and what defense the killer may (or may not) use, here is some information from Wikipedia about the law: “A “stand-your-ground” law states that a person may use deadly force in self-defense...

Homework Statement For archery practice, a knight's squire drops sandbags from a 12.0 metre tower. At exactly the same time the sandbag is dropped, the knight shoots an arrow up at the sandbag from the base of the tower. If the arrow strikes the sandbag at 1.1 seconds, calculate; a) how...

Hello My question is about the ground state of vibrations for a solid. I'm working with graphite and have found out that for k=0 (The Gamma symmetry point), the vibrational modes can be decomposed into irreducible represenations in the following way Vibration = 2 * E1u + 2 * E2g + 2 * A2u...

When the Sun is directly overhead, a hawk dives toward the ground with a constant velocity of 4.15 m/s at 54.5° below the horizontal. Calculate the speed of her shadow on the level ground.Homework Statement Homework Equations vxi=vicosθ vyi=visinθ (i think) The Attempt at a Solution...

Homework Statement Consider the Hydrogen atom in a magnetic field of 2T. If the atom is in its ground state (orbital angular momentum L=0): (a) Write down the magnetic moments of the proton and the spinning electron. [1]Homework Equations I am aware that the magnetic moment μ =...

Hi all, I am trying to interface two separate boards. the power supplies of both the boards are different. One board would act like an output board in the sense it gives either 0V or 24V and the other acts as input board accepting 24V or 0V (any voltage in between as well). Now main doubt is...

Homework Statement A wheel with a radius 50 cm is rolling along the ground at 10m/s[E]. That is, the centre point of the wheel is moving at 10 m/s [E]. - What are the velocities of the top, bottom, front, and back points of the wheel, relative to its center? - What are the velocities...

Howdy - I'm looking for a way to approximate the anchoring strength of a partially buried concrete caisson (pier). It would be used for anchoring a guy wire coming into it at about 45-degrees from above. Most of it's in the ground, a few inches sticks above where the cable fastens to it...

Homework Statement The flag pole is 10m tall. The base of the pole has rusted and the pole topples over. What is the time taken for the pole to hit the ground? s = distance = 10m u = initial velocity = 0 m/s v = final velocity = unknown a = g = acceleration due to gravity = 9.81 m/s2...

The basic concept of a circuit kind of eludes me: Where do neutral/ground/negative wires ultimately go to (i.e. what must the 'thing' they connect to be)? Is it always ultimately the Earth or must it be connected to the actual power generation itself somehow? Example: Could I take a...

Hi, I generally work on embedded boards so i always had this doubt generally in any embedded board with micro controller the pins on the micro controller are located very very close, so if i am trying to see the voltage or some waveform on any of the pins using oscilloscope or multimeter and...

V^2=Ae^-2kx - g/k (upward motion) V^2=g/k - Be^2kx (downward motion) Use the above result to show that , when the bullet hits the ground on its return, the speed will be equal to the expression Vo Vt / (Vo^2 + Vt^2)^0.5 In which Vo is the initial upward speed and Vt= (mg/C2)^0.5=...

What is the difference between neutral and ground?? one more question what is the practical example of current source

Hi, In one of my advanced quantum mechanics classes, the instructor posed a problem, namely to show that the ground state of a one dimensional quantum harmonic oscillator is unique, without getting into differential equations. I know that the equation a\left|0\right\rangle = 0 when...

1. A bullet of mass 0.0020 kg and traveling at 300 m/s strikes the center of a 3.0 kg block of wood which is sitting on a fence post. The block of wood is 2.0 m above the ground. I got the velocity using the eq (m1v1 + m2v2)/Mtotal = 0.2 m/s [correct if incorrect please] I then got the...

Homework Statement A sphere of a mass m and radius R is fired straight up with a speed v0 a) What is its speed when it hits the ground (Include quadratic air resistance but ignore linear air resistance b) Evaluate the result for part (a) with R = 0.2c, v0 = 1.3m/s and m = 100mg I am...

Several years ago I got in a big argument with the folks that wired a new control room (a project I had nothing to do with, but jumped in as a concerned employeed). These guys provided 3-terminal power outlets, but on each terminal they connected the ground to the return, based on the...

Homework Statement A spacecraft approaches the surface of an unfamiliar planet and finds that the pressure of the atmosphere 50 km above the surface is 2.0 × 10^5 Pa. As the spacecraft descends, it is found that the pressure of the atmosphere 40 km above the surface increases to 5.0 × 10^5...

when proton and electron combine to form hydrogen atom(ground state) what is the source of radiation emitted

Metal detectors for searching metals in the ground How they work in one sentence explanation? and second, I've seen some frequency of about 8 kHz mentioned,could that be any possible health risk? Please discuss, thanks.

when a continuous symmetry is broken, we say that the ground state is just one of the possible ground states, and there is no energy cost in moving from one to the other.. why doesn't the state keep changing with the slightest perturbation (production of goldstone boson). why don't we have a...

can "light" excite an electron from ground state to a higher state? An electron of a particular atom can absorb a discrete amount of energy, leap to a new quantum level, and then jump back down to lower states (emitting photons). My understanding is that going from n=2 to the ground state a...

I've tried researching this question and I couldn't find a satisfying answer. How come the water on Earth hasn't been absorbed by the ground over billions of years? The Earth's water evaporate but get's replenished when it comes back down as precipitation. Is there a similar process that...

Hi friendz I have a problem. If a block of mass m is placed over the wedge such that there is no friction then what is the acceleration of block 1with respect to wedge 2 with respect to ground Pleas reply. Thanks in advance. My sir said that it is different.Is it so.

Homework Statement How much energy (in kJ) does it require to remove an electron out of the ground state of hydrogen atom completely, according to Bohr? Homework Equations The Attempt at a Solution

I have a problem with an above-ground water tank supplying a pump on the ground, supplying a sprinkler system. When the pump turns off, the water doesn't stop due to the syphon effect. When I first installed the pump, I put in an adjustable sprink check valve after the pump, but it still leaked...

Why is better to use the cold water pipe as a ground for electrons?

I recently had a discussion with a guy who believes that by putting a big slot in his PCB ground plane he will protect his analog domain from the noise originating in his digital domain. I don't agree with this view (hence the discussion), for various reasons, but to keep this post on point I...

I'm trying to follow a derivation of the ground state energy of Helium using perturbation theory. I've made it through most of the derivation but I'm stuck at the following integral Homework Statement Find the value of C where C=\frac{1}{(4\pi)^2}\int...

Hi, If I have the Hamiltonian: H=(1/2)p^2+(1/24)\lambda(x^2-v^2)^2 what is the best way to find the ground state wave functions \psi(x) . I was thinking this sort of looks like the harmonic osscilator, so maybe a clever change of variables could do the trick? or some form of perturbation...

Homework Statement Already it is on title ! Homework Equations attachents provide the most relevant equations i could find. The Attempt at a Solution I have found some old books written in 1920 decade ,dealing with this subject,but the solution they provide seems very hard...

Homework Statement A particle of mass m is confined to move in a one-dimensional "infinite" potential well defined by V(x)=0, |x|< or=a, V(x)=infinity otherwise. The energy eigenvalues are E(subscript n)=((n^2)(pi^2)(h-bar^2))/(8m a^2), with n=1,2,3,... and the orthonormal eigenfunctions are...

ANYS Static Structural, How to simulate 'ground"? Hello all, first post. I'm having trouble simulating a fixed support in only ONE direction. For example, imagine a gigantic frame laid on the ground and you wanted to see the forces deflect from pulling up on one corner, (the ground...

ground is always considered at 0 Volt? Will this bulb glow and why?

Homework Statement I have this question regarding how i would do the second part of this question as i already know how to do the first part ,but i can't seem to find an approach to the second."What is the speed of the stone at a height of 10m from the ground?" A stone is thrown off the...

Okay so I've seen that some not all power supplies have a positive and negative side for the voltag output and in addition have a common ground connection, exactly what is that used for?

Hi all, I was trying to find the time required for liquid ejecting from a hole in a tank to reach ground level. The equation given in one of the books is as follows: t = √(2h/g) or sqrt of (2h/g). where h stands for the height of hole in tank shell from the ground level. This...

Question: 1. A clock is hanging on wall. length of minute hand is 16cm and the length is 8cm for the hour hand. The highest that the tip of the minute hand reaches above ground is 265cm. a) What is equation of axis, amplitude & period in minutes of function that represents the tip of hour...

Building a wireless energy transfer systems with a transmitting and receiving antenna. I have encountered a problem with what appears to be a floating ground. Initial testing is done with a normal LED that will only light when I have my finger touching one of the leads on the LED. Further...

Hi I noticed that certain workers were laying Pneumatic lines underground ( the lines will be covered with concrete) in a factory. I have no idea how much the pressure would be , or what safety precautions they are undertaking. The lines are used to power certain pneumatic tools ( Torque guns...

I had a curious thought today, here is my logic: Charged particles have E fields. Moving charged particles create B fields. Electrons are moving charged particles, oscillating in an atom. Therefore, I concluded that an atom must be creating an oscillating EM wave, even in the ground state. But...

Homework Statement A 500kg car drives of a 400m cliff located on the surface of the Earth how long does it take to hit the ground Homework Equations F=ma F=mg d=1/d at^2 The Attempt at a Solution i first did f=mg to find f then i did f=ma converted that to find a then did 1/2 at^2 converted...

Hello again everyone! I would like to ask a question regarding this Hamiltonian that I encountered. The form is H = Aa^+a + B(a^+ + a). Then there is this question asking for the eigenvalues and ground state wavefunction in the coordinate basis. The only given conditions are, the commutator...

My textbook tells me that balls don't randomly bounce upward because it is improbable that all of the thermal motion of the particles suddenly align in one direction (upward). But it is just improbable right, or is it impossible? I guess what I'm asking is, is entropy only a statistical...

Forgive me if this seems a rather basic question, but I would like to settle it once and for all. The concept of "ground", "earth" and "common" confuse me a little. I think I have Earth right - this is a path that allows dangerous current to be carried away, eg. if a live wire touched the...