The two blocks ##(m=16 kg)## and ##(M=88 kg )## , are not attached to each other.The coefficient of static friction between the blocks is ##μ=0.33##, but the surface beneath the larger block is...

Friction Force on 2 blocks on a frictionless surface...]]>

I am focused on Section 6.1 The Jacobson Radical ... ...

I need help with the proof of Proposition 6.1.4 ...

Proposition 6.1.4 and its proof read as follows:...

Jacobson Radical and Direct Sums - Bland, Proposition 6.1.4]]>

Could someone help point out certain conceptual errors in my interpretation of the mirror clocks time dilation thought experiment? Say S' is the frame of reference travelling at speed V w.r.t to frame S, which means that events...

Relativity: Time dilation and distance calculations]]>

View attachment 111065

The Young's Modulus of the Material = 290 GN m^-2

The Yield Stress of the Material = 500 MPa...

What pressure would a strain of 40 µε indicate?]]>

Assumptions behind Maxwell's equations for constant speed]]>

How can i get to 5.00v?

I'm making a throttle position sensor test tool. manual is asking for 5.0v +,- 0.01

i plug power in to wall, plug in TPS, use...

have 5.19v dc want 5.00v dc ... need help please]]>

I need to find the pipe diameter or mean velocity.

Q= 0.01m^3s

Density= 960kg m^3

Viscosity = 0.081 Pa s

Max Velocity = 1.8 m s

Mean velocity= 4Q/pi.D^2

I have...

Fluid Mechanics Theoretical Pipe Diameter]]>

I have been reading Sean Carroll's book "From eternity to here" where he mentioned the concept of functioning brains emerging from random fluctuations on a quantum level due to the expansion of universe. They have been called Boltzmann brains...

Expanding universe and the Boltzmann brain problem]]>

find the number of polynomials f(x) that satisfies the condition:

f(x) is monic polynomial, has degree 1000, has integer coefficients, and it can divide f(2x^3 + x)

i would very much prefer that you guys give me hints first....

Remainder factor theorem: please help me reason this out.]]>

Varying electromagnetic field]]>

Pls refer to the second photo , the red line part ....

influence line for trusses]]>

A 415V to 11 kV transformer has a rating of 200 kVA. The winding resistance and leakage reactance when referred to the primary are 0.014 ##\Omega## and 0.057 ##\Omega## respectively.

(a) Determine the % regulation of the...

Transformer calculations]]>

What has happened this year is that Werner Rodejohann and He Zhang, from the MPI in Heidelberg, proposed that the quark sector did not need to match triplets following weak isospin, and then empirically...

What is new with Koide sum rules?]]>

I am a sophomore physics and math major who has realized the importance of being able to code, so I decided to start learning. My question is, what languages should a young physicist learn? I was going to start with C but would like to know where to go from there.

Thanks for the help!]]>

From Pauli spinors to Dirac spinors]]>

or Zn + HCl ----> ZnCl2 + H2]]>

A super cue ball is made of the same material with the target ball (radius r) but slightly larger: r

elastic collision between pool balls]]>

I want to frame out how 75Ω impedance is matched by using tapped coil and two shunt capacitors connected in parallel. I think so for that I have to calculate the load value, and if we take the entire circuit out to be as a load then the most acute hurdle would to be to calculate...

VHF tuner circuit....]]>

Lyman-alpha forest: why not Lyman-beta?]]>

Determine the moment of inertia of a rigid body on the picture:

View attachment 112015

The radius of the inner cylinder is R and the outer is 2R.

3. The attempt at a solution

I thought of...

Moment of inertia of a rigid body]]>

Sec. 23 - Oscillations of systems with more than one degree...

Error in Landau Lifshitz Mechanics]]>

3 - photons have a wavelength, they are QM objects.

Hence my question : are photons the actual wave sources in Huygens-Fresnel principle ? Or are those two...

Are photons the wave sources of Huygens-Fresnel principle ?]]>

It appears very difficult to get a recipie for the liquid to clean in.

I think using distilled water is best. At about 60 degrees celsius.

What fluids are good to use?

I understand that petrol deposits a kind of 'varnish' that can...

Ultrasonic Cleaner Fluids]]>

Why does external pressure on a liquid increase vapor pressure]]>

Calculate the ratio of the drag force on a jet flying at ##1200 km/h## at an atttude of ##15 km## to the drag force on a prop-driven transport flying at half that speed and altitude.The density of air is ##0.38(\frac {kg}...

Drag Force Ratio]]>

I do not know if this is the right forum to be asking this, but it is the best i have found.

A classmate of mine came with the statement that if the earth stopped spinning we would all float off to space because the earths...

Gravity relies on rotation]]>

Angle of pitch and heel for a boat snagged on the side wall]]>

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]]>

It is in Warwickshire England

It moves in the wind

A box one keeps valuables...

All around the world]]>

Please start off with "Today I learned". Keep commentary to a minimum and just LIKE posts. I'll start!

Today I learned that you clean...

Today I learned]]>

Statistics on social media bot use and detection]]>

https://saturn.jpl.nasa.gov/system/resources/detail_files/7547_PIA20506_full.jpg

Webpage of photo: https://saturn.jpl.nasa.gov/resources/7547/?category=images]]>

I've seen this question in several places, with no real worked solution for it, since I correctly did it, thought i would post it here.

A satellite of mass 500 kg is boosted from an orbit...

Finding Change in GPE]]>

View attachment 112045

Above is the circuit I have to deal with. We are given the V

Find the current and Voltage of the following pieces]]>

So, it is not important who makes the measurement first of the entangled pair, Bob and Alice decohere the particle with each other

Bell: Bob and Alice in MWI]]>

I understand that an electron inside an atom/molecule has many possible transitions that it can make from a higher energy state (once it is excited there) to a lower energy state (possibly the ground state but not necessarily). For example, the electron can jump directly from...

Line Spectra correct intepretation]]>

Test Your NASA Knowledge

...

Test Your NASA Knowledge - Comments]]>

Hi everybody! I have the following problem to solve:

An infinitely long and thin straight wire carries a constant charge density ##\lambda## and moves at a constant relativistic speed ##\vec{v}## perpendicularly (##\beta##)...

Relativistic E and B fields of an infinitely long wire]]>

I am happy to re-write the question, but I'm just leisurely working through a list of problems I found online, so here is the link (with picture).

http://web.mit.edu/2.25/www/5_pdf/5_01.pdf

Nozzle Conservation of Momentum]]>

I have got a question concerning the calculation of the overall energy input in random vehicle vibration tests.

I have got different power spectral density levels for different random vehicle vibration tests and would like to compare them with each other concerning the overall...

Overall energy input in random vehicle vibration tests]]>

an article on it in Discover Magazine (July-August 2016, p.68).

I searched for and found several threads here, but were too advanced to

understand and/or did not seem to address my questions below.

BTW,...

Entanglement distance?]]>

Our Beautiful Universe]]>

Simplifying an exponential with a square root]]>

Here is my problem; for example, I have a subroutine,

subroutine test(x, y, z, a, b, c)

The variables...

How does Fortran know the Inputs and Outputs of Subroutines]]>

For me, it's the stupid trig functions. I can't just put angles and numbers on a triangle and solve anything. I have to tell myself "SOH CAH TOA." Every damn...

What menial mental task do you struggle with?]]>

I know, for example, that many current transmitters use a voltage variable conductor to change the frequency of the wave. Did Armstrong do...

How did Armstrong's FM receiver and transmitter work?]]>

Get home from school at 3pm, sleep until 6, work...

Need help finding an ok sleep schedule while in school]]>

Can indeterminate limits always be evaluated?]]>

I am doing a temporary job where I am testing point of sale systems and their ability to handle various types of currency. I have some physical...

What's some of the coolest technology you've used?]]>

"ℝ×ℝ and ℂ are very similar in many ways. How do you realize ℂ as a Cartesian product of two sets? Consider how complex numbers are multiplied; by grouping real and imaginary parts, show how the pattern of complex multiplication...

How to relate complex multiplication to Cartesian products?]]>

Hello!

I'm having a hard time finding realistic black hole simulations, but I saw one recently (black hole size comparison on youtube) that showed the following 3 black holes (attached).

I noticed that the larger the black hole,...

Q: Black hole event horizon vs distortion effects]]>

in my special-relativity texbook i read that, for a generic mass particle system, with respect to a particular frame where the total system linear momentum is zero the mass-energy relation will have a simple, well known and 'satisfactory' form.

Well: what is this frame? its...

linear momentum]]>

Definition(s) of entropy in continuum mechanics]]>

1-##\sqrt {-4}=2i## so ##(2i)^2=4i^2## which its ##-4##

2-##\sqrt {-4}##.##\sqrt {-4}##=##\sqrt {-4.-4}=\sqrt{16} =4##

I think second one is wrong but I couldnt prove how, but I think its cause ##\sqrt...

Complex Numbers in a Simple Example that I am Very Confused]]>

While I'm aware that most fusion experiments to date have used deuterium and deuterium-tritium blends as their fuels, I find myself wondering: can

Ability to produce an energetic plasma]]>

Do carrots really help improve eyesight?]]>

Double slit experiment questions]]>

$$dS = dQ/T$$

Adiabatic Invsicid

$$dQ =0= dS$$

So no heat added or lost no change in entropy I'm fine with that...

Why is Bernoulli's Equation Isentropic]]>

is

##n[A^+B^+] \le n[A^+C^+]+n[B^+C^+]##

In page 174 we can see that this causes linear dependency according to angle. How to derive this?

Let us suppose that angle between ##A^+## and ##B^+##...

Bell inequality and linearity]]>

From the diagram below find the position of the man (##x##) if the system is in balance. Total length is ##L## and the man is distance ##x## from one end.

3. The attempt at a solution

I know that the...

Find the position of equlibrium]]>

$$<x|\Psi>=\Psi(x)$$

The function ##\Psi(x)## is the wave function we are initially introduced to in...

Position representation of the state of the system]]>

If yes, why?

If no, why can't one then measure (in principle) both ##q## and ##p## arbitrarily well at the same time ##p## (which is...

On the Heisenberg uncertainty relation]]>

New member!]]>

since the partial derivative will pick out only the j

Lagrangian for electromagnetic field derivation]]>

I need to calculate radiation power of ball in range 400nm-800nm.

T=10000K

d=1um.

I think I need to use Planck equation and integrate that.

My equation in link: http://imgur.com/XbAUwJ8...

Energy of black body]]>

A. power

B. Current

C. Resistance

D. Both a & b]]>

Anyone else find that music helps them focus? Or perhaps a psychology...

While working on Physics homework, what music do you prefer?]]>

Given an ellipse ##\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1## , where ##a \ne b##, find the equation of the set of all points from which there are two tangents to the curve whose slopes are (a) reciprocals and (b) negative...

Find locus of points near ellipse with some condition]]>

Code (Text):

ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE

1 Raw_Read_Error_Rate 0x000b 071 071 016 Pre-fail Always - 61213753...

1 Raw_Read_Error_Rate 0x000b 071 071 016 Pre-fail Always - 61213753...

So on the left is a circuit which shows a voltage source and 2 coupled inductors in a parallel magnetic circuit shown on the right (transformer with a parallel core).

Can someone tell me if I am modelling it correctly with the following equations?

Rc1,Rc2,Rc3 are the...

Parrallel transformer]]>

3 tuning forks of frequencies 200, 203, 207 Hz are sounded together.find out the beat frequency.

Beat frequency= n1-n2 (n=frequency).

I know that beat frequency...

A question about wave motion and beat frequency]]>

a cylinder sits inside of another fixed cylinder without friction and an internal force acts on the cylinder as shown in the diagram. Draw the normal force vector and write down the force and moment equations.

I drew in my...

Normal Force between two concentric cylinders]]>

Usually, the discoveries on Physics, Engineering, Chemestry and Biology are...

Real advances on CS?]]>

https://www.washingtonpost.com/loca...4def62-dfdf-11e6-acdf-14da832ae861_story.html

I must...

"Women's March" around the world]]>

Here is what I've heard so far:

- Refrigeration systems work based on using heat that is used merely to break attraction of molecules of liquids at their boiling point (eg, freon released through an expansion valve...

Cooling of an expanding gas]]>

In the "perche i nostri discorsi" thread, selfAdjoint gave a concise sketch of the direction that Carlo Rovelli sees in loop gravity

Thanks!]]>

Hi

I am stuck on a small algebra set in the weak limit theorem to recover Newtonian equations

The text I am looking at:

##\frac{d^2x^i}{ds^2}+\Gamma^i_{tt}\frac{dt}{ds}\frac{dt}{ds}=0## (1)

##\Gamma^{i}_{tt}=-1/2...

GR algebra pretty much (weak limit thm)]]>

On Wave Function Collapse and Accuracy of Energy Measurment]]>

Experience with Late SULI Letter of Recommendation?]]>

Alternatively, since the gamma radiation penetrates through materials the most, is there a way of "slowing down" the frequency (lowering the...

Decontaminating Radioactive Materials]]>

I am new to linux and I have a few ports that I need to forward to allow me to play my game

TCP Ports 1119 and 3724 are forwarded.

TCP ports 6881-6999

TCP port 1120

So I used ufw and used the default settings to block everything. Then I allowed the aforementioned ports.

Code (Text):

~$...

Low pressure barometer]]>

Early Quantum Entanglement Experiments basic question?]]>

Either give an example or show that no example exists.

An unbounded sequence for which 3 is an upper bound, and no β < 3 is an upper bound.

example:...

Unbounded sequence]]>

For example, consider Einstein. It is estimated that his IQ is somewhere around 160. Obviously this is well within the top one percent.

But the number doesn't really say how many times...

Is IQ misleading?]]>

Statistical Tests for the Gaussian Nature of Primordial Fluctuations Through CBR Experiments

http://lss.fnal.gov/archive/1993/pub/Pub-93-294-A.pdf .

Here is a quote....http://lss.fnal.gov/archive/1993/pub/Pub-93-294-A.pdf .

Q re Inflation and Gaussian CBR pertubations]]>

Maximum practical size of a BEC]]>

View attachment 112034

I am wondering if in this circuit Vb will be 0V?

I have found all the other ones, but I am unsure if Vb will be 0 or not, and if...

Node voltage with opamp]]>

For the maximum moment occur under the 1.5k load , why when we consider the left part of the beam, we just need to consider the forces 2k and 1.5k only ?

How...

absolute max shear and moment]]>

Is linear polarization not expected from an astrophysical maser]]>

In the first 2 notes , i was told that the absolute max moment will occur under the

absolute max moment]]>

$$H^2 = \frac{1}{3M_p^2} \rho \quad (k=0, flat)$$

In warm inflation, radiation is present all the way therefore not requiring proper reheating process, so

$$\rho = \rho_\phi + \rho_r \, ; \quad \rho_\phi = inflaton, \, \rho_r = radiation$$

But, $$\rho =...

Different forms of energy density in inflation]]>

The Yukawa coupling in the electroweak sector...

Spinor indices on Yukawa coupling terms in electroweak sector]]>

View attachment 112035

I need to find the gain.

I know gain will be Vo/Vs. I originally tried to write different equations for each node, but I ended up...

Analysis with opamps]]>

What's currently going on with the KATRIN experiment]]>