Ground Definition and 945 Threads

I'm new to this site and I'd like to begin my thread posting by asking about the foundations of mathematics. The more I learn math, the less I feel I know and it is getting a little depressing. I have two semesters of college level calculus under my belt (ending the year with Taylor and...

isn't it possible for the gravitational force and the elcetrical origin forces have something very very common fundamentally to both of them

Hello! here is one question which I still donno how to solve: A thunder cloud with a large flat square base measuring 3000m x 3000m passes over an area on level ground. Assuming the cloud carries a total charge of 40C which is spread evenly over its base and is at a height of 0.5 km above the...

Hey all, I was wondering if it would be possible to make a craft that used specially designed rotors or props placed under a craft that were made to take advantage of the ground effect (ie a large surface area, endcaps on them and so on) as long as stability was taken care of by way of auto...

A ball is thrown into the air from ground level. After a time t = 1 s, the ball has traveled to a position x1 = 28 m to the right of and y1 = 13 m up from where it was thrown (at this time, the x and y components of the ball's velocity are still positive). The axes show the x and y directions to...

This name must come up frequently in this forum, but I'm sure it is mostly when discussing "The Bell Curve." Instead of discussing IQ and race I wanted to discuss the topic of Murray's 1984 book, "Losing Ground." Basically, Murray claims that welfare policy is a complete failure that...

I am rewiring my old house (35+ years old) that had non-grounded aluminum wiring (very dangerous!) with good ol' copper/grounded wiring. I have four rooms done and in each room I have put in wall outlets that go to a switch by the door. When I finished the rooms, I used my circuit tester to...

Hi, I'm stuck on this problem: Two solid hemispherical conducting electrodes each of radius r=a are pressed into the earth, curved surfaces down, such that the flat surfaces are flush with the (flat) Earth's surface. Assume that the electrode separation (center to center) is d where d >> a...

Will boiling ground water that contains sulfur produce a yellow sulfur residue. Thanks, --Keith

If we calculate the ground state energy of a system we receive E=w*h(bar). This Energy can be derived with the harmonic oscillator. Is this Energy the Energy of a free photon or a free electron in (for ecample) the vacuum state or is this describing a particle between (potential,...) walls...

1. Why do tires grip the road better on level ground than they do going uphill or downhill? I have some ideas, but I'm not sure how to word them, or if they are correct. Any suggestions would be appreciated. 2. A mass M(1) = 3.5 kg, rests on a horizontal table and is attached by ropes to...

a wooden peg is hit vertically by a mallet which is also moving vertically. The mass of the peck is 0.4kg and the mallet is 2kg. The speed at which the peg starts to move into the ground is 6.67m/s. Given that the ground opposes the motion of the peck with a force of 1kN, find how far the peg is...

When doing L-S coupling scheme for (3d)4, I am asked to find the ground state. I know that the first step, according to Hund's rules, is to find the the S with the largest value (S, L are total values, s, l are individual values). It is obviously S=2. Next, I should proceed to find the largest...

Hi, I am new here, and am not expecting any direct answers (I read the sticky) but I am pretty confused about this one question: A ball is shot vertically upwards at 10m/s from a height of 5m above the ground, If friction can be ignored, what is the speed of the ball immediately before it...

Can someone please explain to me why the time it takes for an object to drop down is the same time it takes to hit the ground if you throw it? Thanks

Has anyone read Gravitation from the Ground Up, B.F. Schutz? What did you think of it? Pete

I asked this question in another thread, but wonder about the answer I got: Question: I bought an atomic-timed clock and wondered if while I am taking off from an airport my clock would record time slower than a clock inside the airport. Since time on the clock is actually maintained by a...

anyone happen to know how to estimate the ground state energy of a vee-box using the uncertainty principle?

Hi - Here's the entire problem to avoid confusion >< "A kite is flying at a height of 500 ft and at a horizontal distance of 100 ft from the stringholder on the ground. The kite string weighs 1/16 oz/ft and is hanging in the shape of the parabola y=(x^2)/20 that joins the stringholder at...

What is the most probable value of r for the grounds tate of hydrogen, and why? Is it just the Bohr radius?

I don't actually have a specific homework question, but I'm wondering if anyone could explain to me how you solve a stopping distance problem. I've encountered these questions in very different ways, once with very little information given, and one with a considerable amount of calculating to...

HELP! plase! help I can't figure out what to do with this assiment that I have this is a sample question. A boy standing in a ditch throws a baseball upward toward his father. The ball leaves his hand at ground level, with an initial speed of 14.0 m/s, at an angle of theta = 59.0 degrees...

This seems like an easy problem but without "time" i"m confused. The best leaper is a Puma that can jump to a height of 12 feet when leaving the ground at a 45 degree angle. With what speed in SI units must the Puma leave the ground to reach this height? I'm not sure what formula to apply...

Relative Motion - I need help on it and more help I need help on Relative Motion. I'm about to literally pull my hair out if I don't understand how to do this. I would very appreciate it if someone could help me out with this one problem and I probably could do the other by myself. The pilot...

I have some problems with the following question: Deduce what terms may arise from the ground state configurations of the atoms of elements of Period 2 and suggest the order of their energies using Hund´s rules. Deduce what terms may arise... Do they mean to which terms the atoms can be...

Hi, I got a few questions on ground effect : 1. When a plane lands, there is a period of ground effect, when the plane is less than 10 feet above the ground and the flight is very smooth. Can someone remind me why it is so smooth? 2. Does ground effect have any effect on regular or race...

HOw can an egg fall from a high placeto the ground without breaking?

The cross-section of a tunnel is a circular arc. The maximum height of the tunnel is 10 (units). A vertical strut 9 (units) high supports the roof of the tunnel from a point 27 (units) along the ground from the side. Calculate the width of the tunnel at ground level. Please help me solve...

Who play these games? Good or not?

Ok, classic old question. Two tennis balls dropped from a very high height. One normal, one filled with lead, for example. So what will hit first? I am certain that they will hit together (theoretically) by looking at the equation v = u + at so no mention of weight or mass. However...

Does Light have a "Ground State"? Light when it gains or loses energy, increases or decreases its oscillation rate, and shortens or lengthens its wave length (respectively). Do anyone find it hard to imagine just how fast and short light was circa big bang? Is it possible, given enough time...

Has anyone ever heard of this place? I live about 30 minutes from its location and I'm trying to plan a camping trip there sometime this summer. Anyhow, a bit of the legend. The area is in a forest, in Chatham County, NC. The particular "tramping" area is a 40 ft circle in the midst of...

Just curios. Why do the electrical outlets in my home have a positive, negative, and a ground? With circuits that I am familiar with, if you have a positive and a negative connected, there is no need for a ground. Does anyone have an explanation? Pan

Problem 9. If a ball is thrown vertically upward on the planet Zeno at 100m/s, then it's approximate height in meters t seconds later is given by h(t)=45t-9t^2. a.After how many seconds does the ball hit the ground? b. How high does the ball go?

Hi, I have to do a report on ground level ozone and was just wondering if that is just another word for smog. Also, I need help in answering the following questions: b) What are mechanisms of the reactions that lead to the production of ground level ozone? c) What is the connection between...

Anybody know why electric charge is attracted to the Earth (ground) ?

I would like to ask the following question about Physics. Question: An object is dropped from a height of 50 m above ground from a helicopter. How long does the object take to reach the ground and what is its velocity on landing if the helicopter (a) is at rest, (b) is ascending with a...

Using the ground state of the hydrogen atom Psi 1,0,0 = sqrt([pi]*a3) * e-r/a I get <r> the expected radius as <r> = 3a/2 where a = Bohr radius. Anybody happen to know if this correct? It would have been cooler if the Bohr radius in physical constants were <r> and the scale factor...

Ok, I am currently taking chemistry, and the course involves some aspects of quantum physiscs, such as bohr models, quarks, and orbitals. My teacher taught us that when the elcetrons become excited they move up an energy level. However they do not move in the traditional sense, "they are...

will you tell me if my answer is correct? An apple falls from a tree and 0.5 second later hits the ground. how fst is the apple falling when it hits the ground. i think it is v = gt 5.0m/s2

A box of mass 32.0 kg sits on a horizontal steel ramp 3.4 m long with a coefficient of static friction of 0.30 between the ramp and the box. The end of the ramp is slowly lifted until the box begins to slide down the ramp. What angle does the ramp make with the ground when this happens? What...

Way, dog, ground, handed? see brain teaser #23

i know that other planets in our solar system have lightning storms and as far as i know its natures way of keeping the electric field between ground and atmosphere in balance, but what would happen if this system had a "glitch" and an imbalance occured, could the atmosphere discharge into...

Here is a question I had to figure out in my grade 11 physics class. "If a 40 kg child is running at a rope suspended from the branch of a tree at 8.0 m/s, and then jumps and grabs it, how high will he swing off the ground?" (I had to translate it so pardon me if it is hard to...

Hi, Why is that, the ground state eigenfunction in ANY quantum mechanical system is symmetric under inversion of co-ordinates?