If so, how fast would that black hole be moving?]]>

I am building a bicycle with suspension on it. The rear wheel is connected to the bike via an axle on a swing arm (a long lever), connected to a linkage lever which is connected to a shock, which has a spring on it. Ultimately I'm trying to calculate the force applied to the shock...

Starting force of a falling object on a compound lever]]>

https://www.physicsforums.com/threads/math-reus-2016.858490/]]>

A friend of mine has twice this week complained about how her job is so tough/stressful and that I should cherish student life while I still have it. She's an accountant and that's what she studied up to...

"Students have it so easy."]]>

Calculate the diameter of a baby's head if there is a time delay of 96 microseconds between receiving pluses from either side of the skull and the speed of ultrasound can be assumed to be 1250m/s.

Calculate the diameter of a baby's head using ultrasound speed]]>

The equation given:

dy/dt = 3*y

According to me it is e^(3*t) but it has turned out false. Why? I am considering the answer "The...

Basis for the space of solutions (ODE)]]>

Bayesian Shirts added to PF Store!]]>

negative curvature]]>

(I) the velocity of the piston relative to the fixed point O (V bo)

(ii) the angular velocity of AB about point A (Wab)

iii) the acceleration of point B relative to...

Offset slider question]]>

For example:

Build a circuit that performs the...

How to synthesize quantum circuits?]]>

Ammonia release into the Mediterranean and coastal cities]]>

Vary acceleration, maximize dτ, Schwarzschild metric]]>

[Maple] Calculating the potential produced by a charge]]>

I Learned C, Now What?]]>

View attachment 111034

The temperature is reduced so much, that the quantum wave states overlap and become one single object.

So what are the properties of this object? Is it...

Bose-Einstein Condensate Properties]]>

If the light passed near star B then due to the mass the will bend, yet if it was to pass through (or try...

The bending of light on a single point]]>

This excresice is supposed to help you understand the basic operations of sets, later used in probability. I am given the following phrases and have to write them in using mathematics.

Calculating events from phrasal expressions]]>

Time to equalization]]>

The title "Speed of time" is the best I can come up with. We know that time isn't constant, rather it depends on the speed at which we move as well as the gravity we are subjected to (see https://en.wikipedia.org/wiki/Gravitational_time_dilation for a reference to the...

Speed of time]]>

In a sealed container is Helium ##M_{He} = \frac {4kg} {kmol} ## with a pressure of ## p_{He} = 4bar##. now is Methan put isothermic inside the container till both the methan and the helium mass are equal( ##M_{CH4} = \frac...

themodynamics: calculating the partial pressure with Dalton's Law]]>

Bohmian Spacetime?]]>

[tex]0\leq |\sin (x^{3}+y^{3})|\leq |(x^{3}+y^{3})|\leq |x|x^2+|y|y^2[/tex]

[tex]|\frac{\sin...

Limit of a two variable function]]>

2. young's double slit experiment...

Revolutionary Physics experiments that changed the world]]>

Sketch of proof: If nullity(T) = 0, then ker(T) = {0}. So T(x) = T(y) --> T(x) - T(y) = 0 --> T(x-y) = 0 --> x-y = 0 --> x = y, which shows that...

dimKer(T) = 0 <--> T is injective]]>

AC current / circuit simulation software]]>

A particle in an infinite potential well ##V(x) = 0, -\frac{a}{2} \leq x \leq \frac{a}{2}##, and infinite elsewhere is in it's ground state. Subsequently, the potential is removed and the particle is free to move.

How does the...

Time Evolution After Sudden Potential Change]]>

for example:

Flat...

Looking for a good sci-fi movie to watch]]>

But what is the model of the universe that is...

What is the appropriate time/matter model for the universe?]]>

Why colonize Mars and not the Moon?]]>

Hello,

I was working on Harold T. Davis

Introduction to Nonlinear Differential and Integral Equations

I saw this following equations

View attachment 113800

1-So equation 4 came as a result of chain rule applies on equation....

Chain rule problem]]>

Thank you.]]>

P(average) for a speaker is 10 W. Gamma is 1.4 (ratio of specific heats), molar mass is 28.8 g/mol, air temperature is 50F, and pressure is 1atm. Find Pmax at 100

I have this equation that gives Intensity = (Pmax^2)/(2*Rho*v)...

Pressure variation with sound waves equation]]>

Definition of an irreducible element in an integral domain]]>

https://www.theguardian.com/science...ication?utm_medium=email&utm_source=flipboard]]>

https://www.cfa.harvard.edu/~loeb/sciam3.pdf

the 3 authors are highly respected physicists in the field

they conclusion

inflation is internally inconsistent and inconsistent with best measurements from PLANCK...

problems with the theory of inflation]]>

What would you do -- summer REU?]]>

Hi guys, would just too make sure my derivation and insight to why is correct.

Question: a) only

View attachment 113840

$$dU=-wd_{ext}$$

$$dU=-F_{ext}...

Deriving an expression for the energy required to separate charges]]>

I am very interested in studying the art of algebraic geometry, motivated by its applications in the machine learning and data analytics. I recently came across Grothendieck's EGA/SGA/FGA saga, and I am really interested in reading it as I like how it presents the...

Tips for reading Grothendieck's EGA/SGA/FGA trilogy]]>

I get the concept of trig parallax and the apparent shift of nearby stars when viewed against a distant background, by viewing the star in say summer and then winter and it appears to move...

Trigonometric parallax]]>

I posted here because I needed some advice from people who are doing better or have experience. So, I am 21 and enrolled in a computer/electrical engineering and computer science program. My first semester wasn’t good. I only passed 1/3 subjects, I studied only two days before the exams....

Need advice (long read)]]>

"Prove: There exists no ##m,n∈ℕ## such that ##m^2+m+1=n^2##."

I basically rewrote it as:

##m^2+2m+1=n^2+m##

or

##(m+1)^2=n^2+m##,

and subtracting ##n^2##, I...

How to disprove (m^2)+m+1=(n^2)?]]>

Semiconductor is the combination of elements in the groups IV and VI?]]>

Max Tolerance stack-up]]>

Thanks in advance.]]>

Why is Hilbert not the last univesalist?]]>

Having Trouble Finding a Math Undergraduate Research Project]]>

1. The problem statement, all variables and given/known data

How much force is needed to push a 20 kg box across a floor at a constant speed of 0.5 m/s [forward] against a frictional resistance of 4 N?

Newton's Second law: Pushing the box]]>

Question:

To solve the integral ##\int \frac{1}{\sqrt{x^2-4}} \,dx## on an interval ##I=(2,+\infty)##, can we use the substitution ##x=\operatorname {arcsint}##?

Explain

3. The attempt at a solution

Integration by substitution question]]>

Velocity: 50 ft/sec

Distance To cross beam: 12 ft

2" x 4" Weight: 9 lbs

I don't know much the cross beam will deflect on impact, so the stopping distance is...

Impact Force of a Horizontal Moving Projectile]]>

And some follow-up news from the Economist:

http://www.economist.com/blogs/democracyinamerica/2017/01/quick-rebuke

In my personal opinion, when I had first heard during the...

US Bans Travelers from Certain Muslim Countries]]>

Please bear with me, you can skip to the LSS (Long Story Short) line if you do not want to go through the wall of text. But the complete story carries important information regarding my demise :).

After a painful 7 years, I managed to obtain my PhD in Physics. My Thesis and...

I am now a PhD, but feel lost about myself and Science]]>

I have been looking at...

Directing Low Frequencies]]>

what is the type of field is exerted by argon plasma?]]>

Prove that [tex]\lim_{x\to a} f(x) = \lim_{h\to 0} f(a + h) [/tex]...

ε-δ proof: lim x->a f(x) = lim h->0 f(a + h)]]>

At time 1:55, Charlie mentions Feynman used to sleep with wives of his undergraduate students.

I never knew about this personal side of him.]]>

I’m doing some numerical studies on diffusion. I began with monte carlo simulations on gas diffusion, and more recently I’ve started to dabble in carrier diffusion inside semiconductors.

It looks like diffusion in semiconductors is a lot more amenable to experimental study...

Does carrier pulse width vary with diffusion coefficient?]]>

Hello everybody]]>

I would like to ask what "file integrity"...

file integrity]]>

Is Sakurai's book a good one?]]>

Leverage and Forces on a Pivot System]]>

∫ d

I realise that the variable has been changed from

proof that parity operator is Hermitian in 3-D]]>

But what happens if, for example, a proton and an antineutron collide? Would a weird nucleus be created or would there be a partial annihilation...

Matter/antimatter collisons between "unlike" particles?]]>

An object with mass of m travelling in a circle rail ,when reached point A the object derailed and moved in a parabola path to point B and so on find the length of AB in term of R and theta. given that B is on the same...

circular motion object falling in the circle]]>

Thanks, hope I understand the waves soon :)]]>

This is my first post here. I will be transferring to University of North Carolina Charlotte (UNCC) in the fall with two associates degrees in Art and Science. I was accepted into the School of Mechanical Engineering. My original plan was to finish my undergrad, then go to grad...

Admittance into MIT Physics Grad School with an Undergraduate Engineering Degree]]>

Interview with Instrument Engineer Jim Hardy

...

Interview with Instrument Engineer Jim Hardy - Comments]]>

1)http://cdsads.u-strasbg.fr/cgi-bin/..._paper=YES&type=PRINTER&filetype=.pdf

2)https://arxiv.org/pdf/gr-qc/9905054.pdf

Conclusion of the...

Particle accleration under gravitational waves?]]>

Let ##X## and ## Y## be non-empty sets, ##i## be the identity mapping, and ##f## a mapping of ##X## into ##Y##

a) ##f## is one-to-one ##~\Leftrightarrow~## there exists a mapping...

Topology by Simmons Problem 1.3.3]]>

Hi,I have got a question as follow:

Compute the commutation relations of the position operator R and the angular momentum L.Deduce the commutation relations of R^2 with the angular momentum L

Commutation relation using Levi-Civita symbol]]>

It is in Warwickshire England

It moves in the wind

A box one keeps valuables...

All around the world]]>

The American Petroleum Institute has published a correlation for determining the hydrocarbon emissions from fixed-roof storage tanks

Ly = (24/1000) * (p/(14.7-p))^0.68 * D^1.73 * H^0.51 * T^0.5 * Fp * C

where: Ly is breathing...

Dimensional Analysis Problem]]>

Crankshaft axis offset from cylinder axis?]]>

Neutral potential ground difference]]>

As I understand it, the principle is essentially that...

Galileo's experiment and a lack of understanding...]]>

White House Blocking reputable News agencies]]>

F(x,y,z) = xz

N/A

I just said that x = rcos(θ) so F(r,θ,z) = rcos(θ)z. Is this correct? Beaucse I am also asked to find curl of F in Cartesian...

Recast a given vector field F in cylindrical coordinates]]>

I was reading some models about the topology and size of the universe (always a controversial topic), then a question came to my mind.

It is predicted that our universe will expand until it reaches heat death. Can a closed, finite universe also reach heat death and be described by...

Can a finite universe end in heat death?]]>

I'm reading through Jackson's Classical Electrodynamics book and am working through the derivation of the Legendre polynomials. He uses this ##\alpha## term that seems to complicate the derivation more and is throwing me for a bit of a loop. Jackson assumes the solution is of the...

Legendre Polynomials Jackson Derivation]]>

Loading / Rapid de-loading of DC motor]]>

the inductance of the coil in Henrys, coil capacitance, the BH max in Joule, or flux density in Tesla,

and volume of the...

Formula for calculating the output voltage of a pickup coil]]>

change of variable and Jacobians]]>

However sometimes, we have problems where you have a ##d(x)## times ## f(g(x))## times g prime of x where we use substitution and it works but the proof didn't prove this...

Integration by substitution]]>

A thin layer of gel (assumed rectangular) is in direct contact with a liquid layer (perfusate) flowing with velocity v in the x direction (left to right) just...

modeling diffusion and convection in a complex system]]>