[ATTACH...

Circular Motion: Write expression for the period in terms of r and g]]>

Turns out that Zoobyshoe beat me in posting about this in another thread, so he will officially be known...

Weird News Compilation]]>

So this is my first homework ever of Hamiltonian dynamics and I am struggling with the understanding of the most basic concepts. My lecturer is following Saletan's and Deriglazov's and from what I have read and from my lectures, this is what I think I know. Please let me know if this is...

Given a set of equations, show if it is a Hamiltonian system]]>

What thickness of ice covering the globe would be needed to melt in order to absorb this amount of energy, assuming that all energy goes...

Volume of ice needed to mitigate ocean warming since 1871]]>

There are conflicting results about it. And even after hours of google searches. I can't figure out what peak should be higher.

In...

Cyclohexane Peaks]]>

How to modify a rotary pencil sharpener to sharpen off-center leads?]]>

So if this ##L[\phi] = M[\phi]## is called an eigenvalue problem (where ##L,M## are operators, could be differential or matrices) then what is this called ##L[\phi] = M##?]]>

Also, when we do it, why when we differentiate a term with a "y" in it, why do we have to multiply it by a dY/dX? What does that...

Questions about implicit differentiation?]]>

I noticed the 1995 cartoon version was more well-received (Tomato score 96%) than...

Ghost in the Shell (1995 & 2017)]]>

Today I learned that you clean...

Today I learned]]>

A glass and bottle of water moving on their own]]>

A reboot of the Invisible Man is currently shooting, with Universal Pictures confirming that it [...]

comicbook.com

Isn't this the same as Kevin Bacon Hollow Man?

Directed by Paul Verhoeven. With Kevin Bacon, Elisabeth Shue, Josh Brolin, Kim Dickens. When the leader of a team of scientists volunteers to be the test subject for their experiment in human invisibility, he slowly unravels and turns against them, with horrific consequences.

www.imdb.com

I...

Invisible Man Reboot]]>

Here's a sketch of the desired device:

Proportionally and size-wise it shoud be similar to a...

Press and release a button to rotate an object?]]>

So here in Australia things are a bit different to Europe (and the US). Here you would usually finish your honours year and then apply to a PhD. How I understand it is in Europe is it goes - BSc, Masters then PhD.

I'm close to finishing my honours year (which includes a research...

European Master's Programs in Physics]]>

Now take the same system with fixed energy U=U

Thermodynamic equilibrium with fixed energy/entropy]]>

But let's start with two masses that are stationary in free space. I don't understand how curved spacetime...

Why Stationary Masses Attract]]>

Question about Galactic Rotation curves in the Milky Way galaxy]]>

[ATTACH...

What's the use of unit vector?]]>

Question regarding the three polarizer paradox]]>

Point P is where I wish to find the magnetic flux density H.

Given the Biot-Savart formula:

$$d\textbf{H} = \frac{I}{4\pi}\frac{d\textbf{l}\times\textbf{R}}{R^2}$$

I can let

$$d\textbf{l} = \hat{z}dz$$

and...

How can I find this formula for the magnetic flux density? (EMagn)]]>

For the x component I got, ## \left< S_x \right> = \frac \hbar 2 (b^*a+a^*b)## which is correct, but Griffiths equates this to ##...

Confused about some notation used by Griffiths]]>

Plumber Steve Lavimoniere...

Your favorite non-Math/Sci YouTube experts?]]>

Greetings]]>

Lambda CDM Model and Spatial Flatness]]>

What is the limit of liquid propane in a tank?]]>

I was working on some homework regarding testing for convergence and divergence of series and I was having trouble with a particular series (doesn't really matter which one) and tried almost all the methods; then tried the Integral Test, my series met the conditions of the...

Testing for Divergence using the Integral Test]]>

I will be graduating with an EE bachelors in a year. To keep this brief, next semester I will be taking courses that branch off from general Electrical Engineering. I have the options of Telecom, Electronics, Control Systems, or Power Systems. Living in the DFW area, what would...

What is the best EE route for someone living in North Texas (DFW)?]]>

Bin center location]]>

What exactly is Weizsäcker's ur-alternatives theory?]]>

Design of a CW multiplier circuit]]>

PF from MS Edge...

Spurious diagonal lines and black screens on Win 10 Pro]]>

I have been lurking the boards for a while, and finally decided to sign up and become a member! I am currently in community college studying mathematics.

NG]]>

From=menu('select:','c', 'g', 'a', 's:'); This is part of my code and I'm not coming up with anything close

Matlab:

`l=input('input wire...`

##m_1= Paula's~Weight⋅2 = m_p⋅2##

##m_2= \frac {Dave's~weight}{2} = \frac {m_d}{2}##

##E_k1= \frac 1 2 (m_p⋅2)(0^2)##

##E_k1= \frac 1 2 (2m_p)##

##E_k1= m_p ##

##E_k2=...

Solve for the total Kinetic Energy change with unknowns]]>

The field of interpretations of relativity is...

Implications of quantum foundations on interpretations of relativity]]>

Estimating a systematic error]]>

Construct a quadrilateral in a Poincare half plane]]>

My understanding may well be wrong, but it is the following.

if a particle is stationary...

Can Lagrangian mechanics be applied to motion in an expanding universe]]>

x(before) | y(before) | x(after) | y(after) | |

puck | (0.36)(13.8)=4.968 | 0 | (0.36)(10.41)cos(α) | (0.36)(10.41)sin(α) |

Collision of a puck and a brick]]>

He wrote the words of many of the Grateful Dead's most loved songs and was inducted with the band into the Rock and Roll Hall of Fame even though he neither played nor sang with them...

Robert Hunter, Lyricist of Many Grateful Dead Songs has Died]]>

Are harmonics "real" in a vibrating string?]]>

My wife just drew this

]]>

The above questions are easily solvable:

1) U = -μBcos(0)

2) U = -μBcos(180)

3) W = ΔU = 2) - 1)

My question is more related to some theory: where is this work/energy coming from since a magnetic force, to my knowledge can't do "work"...

Work/Energy in a Magnetic Field]]>

I've been reviewing the various forum posting guidelines but remain unsure which forum may be appropriate for the following.

I have devised a specialized form of a double-slit...

New User Seeking Physics Feedback and Proper Forum Use]]>

I recently came across a quantum mechanics problem involving a change of basis to a rotating basis. As part of the solution, I wanted to transform the Hamiltonian operator into the rotating basis. Since the new basis is rotating, the basis change operator is time-dependent. This led to a...

Time-dependent unitary transformations of the Hamiltonian]]>

Newton's first law and a body on an infinite and frictionless road]]>

Gas core nuclear reactors?]]>

Modern Physics Understood as an Unrecognized Kuhnian Revolution - Comments]]>

I searched and found no answer to this simple question:

Is the spinning wheel in this videoclip keeping the same rotation (kinetic energy) when flipped upside down and back again?

(if we forget about friction)

]]>

Prompt:

To start off with, I think I'm finding the notation confusing. Specifically I'm not sure...

The Nearly Free Electron Model]]>

Fresh Water from Nuclear Desalination Plants]]>

I've recently started learning about electrical three phase theory, and therefore got some questions.

Imagine the following:

Countries like Albania, Norway ++, have IT earthing configuration in their distribution grids, i.e. the neutral point is not solidly grounded, however "grounded"...

Unbalanced 3 phase power - what happens without a neutral wire?]]>

I basically just needed to calculate the original capacitance of this capacitor using c...

Find the charge on the plates of a parallel-plate capacitor w/ dielectric]]>

- Are there significant...

California Fires and Electrical Reliability Around The World]]>

I recently finished applying to a university for grad school. Previously, I had contacted a professor with whom I wanted to work with, and it seemed they were also interested in taking me as a PhD student. Ideally, would one follow up (by email) with the professor once they've...

Following Up with Potential PhD advisor after Applying?]]>

Need help with 2 Kinematics questions (New to forum and physics)]]>

]]>

$$g = \begin{bmatrix}a^2t^2-c^2 & at & 0 & 0\\at & 1 & 0 & 0\\0 & 0 & 1 & 0\\0 & 0 & 0 & 1\end{bmatrix}$$

Using the adjugate method: ##g^{-1}=\frac{1}{|g|}\tilde{g}## where ##\tilde{g}## is the adjugate of ##g##. This gives me...

Coordinate transformations on the Minkowski metric]]>

I started by converting it into radian.

Then i wrote as ##I=Cos(\pi/45)Cos(2\pi/45)....Cos(22\pi/45)

Also I=Cos(44\pi/45)Cos(43\pi/45)....Cos(23\pi/45)##

And then i multiplied the two equations.But it didn't helped me.What shall i...

A Tricky trignometric Problem]]>

I have been looking for an answer to this question and came across this PF article (https://www.physicsforums.com/threads/why-is-iron-56-the-most-stable-nuclei.635183/) which explains most of the type of answer i was looking for.

So as I understand ( Quantum Pion's thread from...

Why does Nickel-62 have the highest BEPN?]]>

What I understand from the figure :

T

T

T

- The three masses given all have different mass so each of them...

Help with a pulley problem with 3 masses]]>

1. JBA

2. kuruman

3. Andy Resnick

4. Marzena

5. Rubidium_71...

VOTE PF Photo Contest - Are You Looking At Me?]]>

I have understood the following: in SR, time intervals and space intervals (distances, lengths) are relative and inertial reference frame dependent. Space and time is not absolute anymore. However, acceleration is still absolute: different inertial frames see the same acceleration...

The Equivalence Principle as a Starting point of GR]]>

As a personal project,I am currently designing a mechatronic hand, with a number of DOF similar to our hand. I've choose to transmit the axial movement of a finger through a rotary motion, because cable where causing too many backslash an other linear transmission became severely more...

Motion transmission through a mechatronical wrist]]>

1. What is a parallel displacement of a coordinate system?

Does it refer to moving along any axis...

Landau's Derivation of the Lorentz Transformations]]>

I'm a retired accelerator physicist entertaining myself by trying to understand physics questions like entanglement better. I calculate the expectation value of the product of two electron spins in the singlet state...

Calculate the expectation value of the product of two electron spins in the singlet state with measurements]]>

How do charts on differentiable manifolds have derivatives without a metric?]]>

Gold absorbance of blue light]]>

Until his work, Mayan writing was not understood and many thought they were just pictures.

This kind of work was limited by lack of material as most examples of Mayan writting was...

Michael D. Coe, Decoded Mayan Writing, is Dead]]>

If liquid contained within a finite closed circular cylinder rotates about the axis k of the cylinder prove that the equation of continuity and boundary conditions are satisfied by

Fluid Mechanics: Liquid contained within a finite closed circular cylinder rotates about the axis]]>

And if they are left in the forest and then rot 90% of their mass also go back into the atmosphere.

Here in Germany we have many old salt mines.

I wonder if it would be a good idea to cut trees and store...

Store wood in old salt mines to reduce CO2 in the atmosphere]]>

What is the easiest way to synthesize AlBO3?

Thx!

I want to synthesize silicon allotrope. Not just cubic silicon, but orthorhombic.

But in the first step, I need to synthesize Li7Si12.

Is it possible or not?

Any ideas about how to do it?

The main idea can be found at this...

Silicon allotropes]]>

]]>

Uncollapsed(stateless | unphysical) Quantum Waves + State(Matter Field or wave collapse) = Physical Matter

Is a Matter Field state change the same thing as...

The key to unifying the theories of the very large and the very small]]>

I am looking at using solar panels to accomplish two things:

-I want to power a heating element submerged in a water tank to act as a thermal battery for heating a chicken coop

-I want to also charge a relatively small 12V battery by connecting the panels to charge controller...

How Do Solar Panels Behave?]]>

In the drawing you can see a circumference inscribed in the triangle ABC (See the picture in the following link). Calculate the value of X

https://goo.gl/photos/CAacV2dJbUrywfXv9

It seems I found a solution for...

Circle inscribed in a triangle exercise]]>

Any help would be greatly appreciated]]>

Is QM deterministic? Specifically, in the case of MWI? Is it time reversable?]]>

Is renormalization the ideal solution?]]>

Canonical momentum $\pi^\mu$ of the electromagnetic field]]>

Finding my first job opportunity]]>

Physics Depth Study in Advanced Mechanics -- investigating the motion of rockets and satellites]]>

This is a piece of common red/black loudspeaker cable, with PVC insulation, pulled from service after about 18 months from installation. It was used to feed a...

Insulated copper wire turned into gray powder]]>

Kinetic friction is friction that occurs when something is moving and rubbing against another surface, creating such a friction. Your photo must clearly depicts a scenario in which such a thing is occurring. In includes cases where the...

PF Photo Contest - Kinetic Friction (10/12-10/18)]]>

Dear all.

I don't...

Fourier transform and derivation]]>

I tried to use ##W = ε_0/2 \int E^2d\tau## for all space. So I find that ##E = \frac{(R^3 - b^3)\rho}{3ε_0r^2}## where ##\rho## is the charge denisty. So from here when I plug the equation I get something like

$$W = \frac{(R^3 -...

Electrostatic Energy of a solid sphere with a cavity]]>

Placement of disc brake calipers for best performance]]>

For example, consider this video among a few thousands on...

Problems with soldering]]>