Comparison of tidal forces acting on the Moon vs Enceladus]]>

What is x ?( Assuming x and y are positive)

1000/x=3600 + (3600(y-x)+1000)/x+y

Calculator gives it as x=5/36 but I cannot find a way to get that?]]>

Failure description:

In the deep groove ball bearing only one rolling element has a pre-mature fatigue failure (Image-6.jpg) and rest of the all ball is in good condition (image-05.jpg).

Do any one has seen the same kind of...

One Ball fatigue failure at Deep Groove Ball bearing]]>

Best books and papers for classical "hard" analysis tricks]]>

Consider gamma matrices ##\gamma^0, \gamma^1, \gamma^2, \gamma^3## in 4-dimension. These gamma matrices satisfy the anti-commutation relation

$$

\{ \gamma^\mu , \gamma^\nu \}=2\eta^{\mu...

Clifford algebra in higher dimensions]]>

Software - Suspension Analyzer by Performance Trends

In order to understand the complexity of a Formula Cars suspension, a basic knowledge of the stock car suspension should first be mastered. When...

Race car suspension Class]]>

However I recently found out that there also is a thing 'Hollow optical...

How can light propagate through Hollow optical fiber.]]>

Non-rectangular PV Panels: do they exist?]]>

Measurement problem in the ensemble interpretation]]>

How to calculate Toroidal Core Maximum VA capacity]]>

My "ancient mythos" choice is: The Grey Mouser....

And who is your Swords+Sorcery or Fantasy character?]]>

What are the requirements for...

Is it possible to fly horizontally using augmented fly pack?]]>

No major repairs on it are needed at the moment. But just curious if there is some formula for determining when it's best to buy a "new" (really I mean "newer," since I'm open to used cars too) car when your current old one has gotten up in age...

When to Buy "New" Car if Driving High Mileage Old One?]]>

actual example of a mixed state not part of entangled state]]>

I saw this beautiful old machine on eBay, and couldn't resist it. Comes in a brass case with carry handle, and is encased in walnut-effect Bakelite. The screws and terminals are solid brass, and it actually smells of pipe tobacco.

I have tested it, and wonder if...

Evershed and Vignoles 500V hand-cranked megger]]>

Here is the thing I am working on a project where I am manufacturing Furfural from bagasse. The reaction is thermodynamically possible. I took some amount of bagasse and added it to a reactor at atmospheric pressure. I then added diluted Sulphuric acid which acts as catalyst,...

Quantitative analysis.]]>

A rocket propels itself rectilinearly by giving portions of its mass a constant (backward) velocity ## u ## relative to its instantaneous rest frame. It continues to do so until it attains a velocity ## v ## relative to its initial rest frame. Prove that the ratio of...

Special Relativity - Rocket problem (particle mechanics)]]>

Can physics be explained in plain English]]>

modern usage of non-navigational radio beacons]]>

About half of college grads underemployed=>disaster?]]>

I need to know which is better to have many PRF tubes with less volume or to have single PFR tubes with large volume? How to decide what is better ?]]>

Hydrostatic equilibirum in slowly rotating star]]>

Resources for air flow/air compression physics]]>

Consider this definition of the Dirac delta:

$$\delta (x-q)=\lim_{a \rightarrow 0}\frac{1}{a\sqrt \pi}e^{-(x-q)^2/a^2}$$

First, this would make a normalized position eigenfunction

$$\psi (x)=\lim_{a \rightarrow 0}\frac{1}{\sqrt{a\sqrt \pi}}e^{-x^2/2a^2}$$

right?

If that is so, why do...

Questions about the Dirac delta]]>

Is symmetrical AWD more efficient at acceleration during high speed...

Symmetrical vs Asymmetrical AWD at high speeds]]>

Non-sinusoidal sound waves]]>

how accurate is it? Is there a size limit for any spectrometer where accuracy could be affected?

the Scio is an IR spectrometer.. is pocket size...

pocket size molecular spectrometer]]>

Microvolt pulse Detector]]>

The problem involves a population in a country:

(millions)

Part A involved finding the population in 1920 using Newton Divided...

Finite Differences]]>

Given a scalar function ##f## find (a) ##∫f \vec {dl}## and (b) ##∫fdl##

along a straight line...

Line Integral Notation wrt Scalar Value function]]>

Playing trombone to 'wildlife':

]]>

I may have discovered a textbook error but I'm no calc whiz. I need an assist to find out if the question unintentionally described a square instead of a rectangle.

I have attached the textbooks solution as well as my attempt at a solution.

The numbers check out, I just want to make sure...

Rectangle optimization - possible text error]]>

In an infinite flat layer of thickness 2

Time period of small oscillations of the point dipole]]>

Creating a simple password program in C++]]>

Can a microorganism change behavior of an animal? ( including humans).

Thank you for your time.

Regards,

ORF]]>

Charged basketball, inertia ball and field]]>

IT Dept Quality, like % of budget devoted to IT department, Number of External Audits, etc ; each is measured on a Likert scale. I ultimately want to regress EDIT against...

Composing Likert "Subvariables" into a Single Variable]]>

Atmospheric Heating from Meteorite Impact]]>

I worked for a professor during the summer (for free) in high energy Physics trying to plot the signals from a function generator to a computer using a microcontroller. He was really impressed with my work (basically, he...

Physics lab coordinator?]]>

I am trying to copy info from MATLAB to Excel via the following code

Code (Matlab M):

filename = 'testdata.xlsx';

A = [12.7 5.02 -98 63.9 0 -.2 56];

xlswrite(filename,A)

Warning: Could not start Excel server for export.

XLSWRITE will attempt to...

Matlab to Excel]]>

2. If not, then can I get a PhD in nuclear physics with a double major in mechanical engineering and mathematics,...

Nuclear physicist with nuclear engineering PhD?]]>

What would power level DC-DC transformers be good for?

- Connecting different voltage level...

DC-to-DC Power Transformer]]>

I thought the same should be the case for gravitational time dilation; if a clock on a tower runs n times...

Uniform-gravitational time dilation -- exact or approximate]]>

Is it possible that an electron can have a negative mass?]]>

Triple Major -- EE / ME / CS]]>

Sound Waves -- propagating, dispersing, volume effects?]]>

The function is f(x)=x+cos(x) and the interval is <-PI,2pi>

There is an attached solution but I do not understand how to arrive at the given solution (see screenshot). I would personally just take the...

Maxima minina on an interval (calculus+trig)]]>

I have to teach a group of 9th grade students

role of resistor in a circuit and how it affects the current in the circuit . This will be their first exposition to circuits .So I need a good and simple analogy so that students can grasp these concepts easily .

This is what I plan to...

Resistor and current in a circuit]]>

First, we...

How to calculate probability of seeing someone you know]]>

The problem is in the context of convection in the troposphere

Show that when an ideal gas expands adiabatically, the temperature and pressure are related by the differential equation

[tex]\frac{dT}{dP} = \frac{2}{f+2}...

Adiabatic Expansion Pressure Temperature Relation]]>

Divergent Diagrams in the Standard Model]]>

By un-reasonable , it means a friend asking for 5 lectures worth of notes, not 1 or 2 and for no apparent...

Sharing class notes]]>

The following is the typical raman spectra of water.

View attachment 207567

In their normal form, water molecules maintain a simple configuration: an oxygen atom is in the center and two hydrogen atoms are on the two sides symmetrically. Under ambient conditions, water molecules...

Raman Spectroscopy question]]>

Buoyant object rising in water pulls on a cord attached to a generator. How much power is generated?

Object Volume = 100m2

Liquid is plain water = H2O

Depth = 100m

I understand that Archimedes Principle is the buoyant force = the weight of the...

Calculating the electrical energy of a buoyant force]]>

Tr(T

I think other places call this a killing form, but I may be mistaken. In any case he discusses reducible...

Index (killing form ?) in a reducible representation]]>

Information from a black hole]]>

View attachment 207520

Every small part of the trajectory can be taken as a circular arc.

Then,

$$\frac { m v^2} R ≤ kmg $$

But how to find out R from...

sine curve trajectory]]>

"A central...

How to do the calculations showing the Universe is flat?]]>

Fast Radio Burst Pinned Down to Giant Stellar Nursery

by Ken Croswell

A young neutron star is probably the source of a repeating signal previously tracked to a dwarf galaxy 2.4 billion light-years away.

Link:...

Fast Radio Burst Pinned Down to Giant Stellar Nursery]]>

a(t) ~ e

Inflation: meaning of χ (chi) for time scales?]]>

(I...

“Vector” operators]]>

I am not sure i should use wide or length. i mean the rightest point of horizon to the leftest point of it for human' eye angles.]]>

Background: I have a BA in Communications (3.3 GPA) and have been a writer for 10 years. I went back to school last year in the Midwest to pursue...

Second Bachelor's Degree in Physics in Boston]]>

i want to attenuate the sound blast from a rifle muzzle, however, i want to engineer a large deep room to do it. think of this like a indoor firing range. i know opera stages many times dont...

Engineering Sound Stage]]>

That's my problem--that illusion is so vivid and stubborn.

Paul Davies said in his book "About Time": There is only one rational conclusion to draw from the relative nature of...

Block universe discussion]]>

Age and size of the Universe?]]>

There is a great explenation of this problem in the MIT paper but...

Biot Savart Law]]>

Analyzing Curvature with Confidence Bands?]]>

Our Beautiful Universe]]>

It's original purpose was to convert car windows to electric drive... my guess is that it is at least 25 years old, and made in Japan.

For scale... the width of the motor casing is 50mm (as you look at it)

View attachment 206911 ...

DC12V 12A car window motor - what spec for a 220V PSU?]]>

P.S. I'm also interested in books which involves other fields (eg. chemistry) and DIY projects]]>

$$\bigg( (1-z^2) \frac{d^2}{dz^2} - 2z \frac{d}{dz} + l(l+1) - \frac{m^2}{1-z^2} \bigg) P(z) = 0$$

Solving this equation for ##P(z)## is one step in deriving the spherical harmonics "##Y^{m}{}_{l}(\theta, \phi)##".

The problem is that the book I'm following...

Spherical harmonics]]>

Terry Tao's Interesting View of QM]]>

U.S. Solar Eclipse of Aug. 21, 2017]]>

View attachment 207790]]>

"Natural Born" Androids/Cyborgs]]>

A stone falls from top of a well, 10 seconds later sound of water splash reaches the top of the well. How deep is the well?

g=9.82m/s

2. Relevant...

Free fall and distance]]>

Nuclear Plant Batteries]]>

Is this a good book to get and start from page 1...

physics textbook for undergraduate level, self study]]>

I have done three years in my undergrad in physics/math and this summer I'm doing a research project in general relativity. I generally use a computer to do my GR computations, but there is a proof that I want to do by hand and I've been having some trouble.

I want to show that...

Two Conserved Quantities Along Geodesic]]>

How do programmers keep it all straight?]]>

Two particle interference]]>

Because of the Coriolis force, falling objects on the Earth are deflected

horizontally. For instance, a mass dropped from a tower lands to the

east of a plumb line from the release point. In this example

Deflection of a Falling Mass]]>

Thanks to PF members and PF threads, and reading about astrophotography, I succeeded the first time. This was just some tests I did with my mobile phone, LG G4, which has a pretty decent camera which...

Mobile astrophotos premiere]]>

Equation 5 in this paper states that

$$\frac{\partial F}{\partial p_i} = 2Re\left\lbrace\frac{\partial F}{\partial x}\frac{\partial x}{\partial p_i}\right\rbrace$$

Here, [itex]p_i[/itex] stands for the [itex]i[/itex]'th element of a vector of...

Question about derivatives of complex fields]]>

I have a rigid rod which is hinged at a point and can pitch or heave about that location. There...

2-DoF system characterization with 2 dual axis accelerometers]]>

Quantum bits information lost in black holes]]>

I am currently working on an Arduino project that involves multiple stepper motors. The motors are told how to move by an external txt file. However, sometimes the processing of how the steppers have to move takes longer than the actual movements themselves. Some movements should only...

Reading a lot of data very quickly with Arduino?]]>

I am working with a system such as this one, with only a few differences: http://www.sciencedirect.com/science/article/pii/S0168583X1400706X

it is a cryogenic stopping cell....

Rectangular wave, extraction of ions from a stopping cell]]>