Which undergrad comp sci courses would be helpful for stats?]]>

The rockets of the Goths and the Huns are each 1000 m long in their respective rest frame. The rockets pass each other, virtually touching, at relative speed of 0.8 c. The Huns have a laser cannon at the rear of their rocket...

special relativity application]]>

First, write the polynomial in this form:

$$a_nx^n+a_{n-1}x^{n-1}+......a_2x^2+a_1x=c$$

Let the LHS of this expression be the function ##f(x)##. I'm gonna write the Taylor series of ##f^{-1}(x)## around ##x=0## and then put ##x=c## in it to get ##f^{-1}(c)## which will be...

Can Taylor series be used to get the roots of a polynomial?]]>

A charge -3.2 micro-coulombs is spread evenly throughout a rod of length (a). At a distance (b) from the rod, what is the electric field?

a = 1.2 m

b = 3.4 m

So basically, you start at zero and then there's a line of charge...

What is the electric field at this point?]]>

I am currently analysing the forces acting on a moving vehicle. The vehicle is mounted on a rail with wheels on both upper and lower side of the rail with a spring increasing the reaction force, and thereby the...

Torque needed to accelerate rail-mounted vehicle]]>

I need some help to calibrate argon spectrum.

I have a MicroLab Spectrometer (Model 141) to obtain spectral images of argon plasma. To calibrate the spectral images, I need a reference of known wavelength.

Usually, a discharge tube is used to obtain the reference spectrum. However, I...

Spectrum Calibration]]>

[A(

What is the physical significance of Bell's math?]]>

Insulator has a 3 cm radius and is a sphere. It has a total charge of -4.2 uC. I need to find the charge density of the insulator.

sigma = total charge / volume.... I think?

What is the charge density on the insulator?]]>

View attachment 113488

Edit* should say F'(0) = F(0) = 0

I know that I typically need 3 equations for a 3rd order ODE, does this apply if the is no F'? In the picture above are the equations I...

Runge Kutta to solve higher order ODE]]>

$$\cos\Theta_{W} = M_{W}/M_{Z}.$$

Can the Weinberg angle ##\Theta_{W}## be expressed in terms of the Higgs mass and the mass of the W boson as

$$\sin^{2}\Theta_{W}= m_{H}/M_{W}?$$]]>

The first one is about the Bohm and Pibram as well as one about Alain Aspect 1982 study: articles about their theories:...

Hologram theory and quantum physics = existential crisis]]>

Design a lag-lead compensator for the system of Figure 9.37 so that the system will operate with 20% overshoot and a twofold reduction in settling time. Further, the compensated system will exhibit a tenfold improvement in...

Control Systems - How to find dominant poles *without* MATLAB?]]>

I have several confusions regarding Faraday's law of induction.

[tex]EMF = \int_{}^{} {\vec E \cdot d\vec l} = - \frac{{d\Phi }}{{dt}} = - \frac{d}{{dt}}\int_{}^{} {\vec B \cdot d\vec S} .[/tex] It means that If the magnetic flux

Some confusion of Faraday's law of induction.]]>

Observer O at the origin of a coordinate system is at rest relative to two equidistant space stations located at x=+3.00×10^6km (station A) and x=−3.00×10^6km (station B) on the x axis. In reference frame O, station A sends out...

Distance between two events in a moving reference frame]]>

Hydrogen peroxide can be prepared in several ways. One method is the reaction between hydrogen and oxygen, another method is the reaction between water and oxygen. Given the ΔG°rxn values for each reaction, which method...

Free Energy - Physical Chemistry]]>

Firstly I'm sorry about language. In Turkey, Our education system does not adequately support English. Anyway.

What is the evidence about gravity is exist. Wait. I mean, we know something pushing...

What is the evidence that there is gravitation?]]>

Any ideas about the book ?]]>

I can find the e-field at point P.

View attachment 113460

I get, easily enough, the correct integral solution (for the y-component, E

Evaluating a simple electrostatic field integral]]>

Now my question is :

What’s the relationship between entropy in the information-theory sense and the thermodynamics sense?

I need some clear and...

The Term "Entropy"]]>

Then there are these...

Are there different "types" of renormalization]]>

Cosmology Lectures]]>

Once I let go, both masses would follow geodesics in spacetime towards the center of the planet. Because the masses travel radially, the spring would compress and...

Tidal forces on a spring mass system]]>

Interference pattern after a particle is detected?]]>

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]]>

Assume that the potential is symmetric with respect to zero and the system has amplitude ##a##, show that the period is given by : ##T=\sqrt{8m}\int^a_0\frac{dx}{\sqrt{V(a)-V(x)}}.##

##E =...

Oscillation Period]]>

Do photons carry magnetic force?]]>

A 100 kg block is pushed across a level frictionless surface at a 60 degree angle, with a force of 20 newtons. How many seconds does it take to go 100 meters?

m = 100kg

Mu = 0

F = MA

How long does it take to push this block at an angle?]]>

Using an expression that relates luminosity, size and temperature of a star, and assuming all Main Sequence stars have the same mean density, determine the...

Stellar Radius & Effective Temperature]]>

Hello guys, I was using mcnp code SERPENT, and while defining materials i encountered a problem. The problem is that for example: if i'm given that i have a 3.5 percent enriched U-235. how do i find the rest of the mass percents...

Calculating Mass Percent in UO2 Nuclear Fuel]]>

Blue Light]]>

From 250 to 200 million years ago, all the continents had joined together to form a singular landmass called Pangaea.

The...

Great Lakes Earth (WHOLE)]]>

thank you]]>

Future Cosmology:]]>

Hello all,

I have a question regarding the damping constant for a model of a vertically oscillating mass on a spring. I have read through one or two similar questions on this site but I think I can manage to be a little more...

Theoretical model for damped harmonic oscillation.]]>

cryptography notation question]]>

As I...

Diffeomorphisms & the Lie derivative]]>

Unfortunately, this meeting was scheduled for now [in the middle of the semester], rather than its usual time in January [during my break]. So, I wasn't able to make it.

However, the...

AAPT 2017 Summer Meeting-Cincinnati, OH (Jul 22-26, 2017)]]>

$$U_t=\alpha^2 U_{xx}+VU_x$$

I understand that in this situation you can transform to a moving coordinate system and the convection term will dissapear and you can solve for diffusion alone and...

diffusion and convection in moving fluid]]>

If the steel disk has mass of 200 kg and a radius of 2 meters you can make it spin by applying a force to the rim. This torque increases the angular momentum of the disk. Suppose the force is 20 newtons. How long would you...

Angular Momentum Question concerning a Merry Go Round]]>

Show that a group with no proper nontrivial subgroups is cyclic.

If a group G has no proper nontrivial subgroups, then its only subgroups are ##\{e \}## and...

Show that a group with no proper nontrivial subgroups is cyc]]>

both of these notes are in the same chapter . So , they are relevant to each other ... In the first picture, what's the difference between the 2 circled part ? The first one is W = 0.5 P Δ , the second one is W = P Δ

.....

Work to elongate the things]]>

I would like to plot Vout vs Vin for the following circuit:

Square law equations for MOSFET transistors.

I'm...

Help me understand this MOSFET circuit?]]>

Solve for ##\theta##:

##\cot \theta \sin \beta + \rho \csc^2 \theta = \cos \beta##

where ##0^\circ<\beta<90^\circ, \ 0^\circ<\theta<90^\circ##, and ##0<\rho<1##.

##\cot^2 x +1 = \csc^2x##, the...

Grinding Angles]]>

Here ##Si(x)## is the integral of ##\frac{\sin{x}}{x}##

But, to check it, I need to evaluate the ##Si(x)## function. I'm new with Taylor...

Expression of ##sin(A*B)##]]>

Generalizing the definition of a subgroup]]>

$$tan^{-1}(a+b)\approx \frac{b*tan^{-1}2b-a*tan^{-1}2a+\frac{1}{4}*ln\frac{1+4a^2}{1+4b^2}}{b-a}$$

$$sin^{-1}(a+b)\approx \frac{b*sin^{-1}2b-a*sin^{-1}2a+\frac{1}{2}*(\sqrt{1-4b^2}-\sqrt{1-4a^2}}{b-a}$$

And, similarly for...

Expressions of ##log(a+b), tan^{-1}(a+b),sin^{-1}(a+b)##,etc]]>

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]]>

CO2 is at P=3atm, T = 295K and V=1.2m

It is isobarically heated to T = 500K.

Find ΔU and ΔH

dU = c

I am having a hard time in general...

Internal Energy Thermodynamics]]>

Can anyone recommend a good linear algebra/ODE book?]]>

My question is regarding showing closure. To show that the subset is closed...

For groups, showing that a subset is closed under operation]]>

Find ##f(x)## such that f(f(x))=##log_ax##]]>

I am experimenting with some widely known microwave susceptors like iron oxide and silicon carbide (materials that normally convert RF to heat quite effectively). In ceramic formulations they perform great, as expected. When...

Are microwave susceptors attenuated in viscoelastic mediums]]>

"“We love this decay because it is one of the most...

decay of the Bs0 particle and supersymmetry]]>

First: When a physics problem says "sliding past point P" does that mean it...

Some questions about terminology]]>

So consider the transformation of an arbitrary vector,

Entries in a direction cosine matrix as derivatives]]>

Nuclear reactors and nuclear bombs]]>

I built a small application which I figured some users here may be interested in. The app aggregates news and events in the space industry, allows you to view launch schedules, track the space station, and more.

It's called Luna and an early version is available on the Play Store:...

Space news and events aggregator app]]>

that the potential energy is in the lifted mass.

This cannot be. Consider the case of two perfectly rigid spheres, isolated in...

Where is potential curvature stored in GR?]]>

Or is that just a super facile explanation of expansion that they explain people like me who wouldn't get it?...]]>

A triangular prism of mass

a newton law question which is too hard for me]]>

I'm looking at determining the inverse Laplace transform of a simple exponential F(s)=exp(-as), a>0. It is known that in this case f(t) = delta(t-a). Using the Bromwich formula,...

inverse Laplace transform of F(s)=exp(-as) as delta(t-a)]]>

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

An amusement park ride consists of a large vertical cylinder that spins about its axis fast enough that any person inside is held up against the wall when the floor drops...

Amusement Rotor Ride Explanation]]>

However...

Parallel/Series DPDT With MOSFETs Help?]]>

Public Perception of Science]]>

Here is his definition of wave-particle duality....

My question relates to electronics soldering, where the main metal in the solder is Sn, with small amounts of Ag and/or Cu

If a rod of Cu, Ag, or Au is placed in molten Sn, which of the rods would melt away fastest?

Is there a threshold temperature up to which the solid metals won't...

Metallurgical questions about alloying of Sn with Cu/Ag/Au]]>

Is this why we look to binaries, so that there is some rotation of the objects with respect to each other breaking the spherical symmetry? Or mainly because the gravitational radiation is much greater...

Why binary systems for gravitational waves?]]>

Advice on reading an entire physics textbook in one semester]]>

Title

This would seem to be very easy problem, since it's intuitively obvious that if two groups are isomorphic, and one is cyclic, then the other is cyclic...

If G is cyclic, and G is isomorphic to G', then G' is cycli]]>

Design of CT with ferrite core for reverse operation of CT]]>

Anyway... I'm almost...

Recently finished HEP Ph.D. but unsure of next move...]]>

CFD turbulent fluid, discussion about pressure gradient]]>

Physics of Human Caused Earthquakes?]]>

In ceramic formulations they perform great, as expected.

When formulated in silicone rubber, they do not perform when subjected to...

microwave susceptors are suppressed in viscoelastic mediums]]>

Unfortunately, it only have 4...

I love my smartphone]]>

Here is the last page of part 5.

https://www.physicsforums.com/threads/random-thoughts-part-5.851969/page-134]]>

I know that there are so many videos on adjustable springs on garage doors but I think all they do is adjust...

Adjustable Torsion springs]]>

PF Photo Contest - Bigfoot (2/18-2/24)]]>

Unless there are natural processes that uses fission or heat from slow fission (maybe heating up the earth)?...

Natural Fission]]>

Moving charges and varying magnetic fields]]>

Each week, Stéphane needs to prepare 4 exercises for the following week's homework assignment. The number of problems he creates in a week follows a Poisson distribution with mean 6.9.

Statistics probability questions]]>

I have come across two definitions of eigenstates (and eigenvalues), both of which I understand but I don't understand how the two are related:

1) An eigenstate is one where you get the original function back, usually with some multiple, which is called the eigenvalue.

2) An eigenstate...

Eigenstates & Eigenvalues]]>

dt = measured time interval between left...

Sound-bearing equation]]>

Prove that a group has exactly one idempotent element.

So we need to show that the identity element is the unique idempotent element in a group.

First, we...

Show that a group has exactly one idempotent element]]>

Curvature of Flat Lorentz manifolds]]>

Multiple Beer Capper]]>

Experiments probing macroscopic limits of QM]]>

Unusual gravitational observation...answers?]]>

1.0 0.014.

1.5 0.032.

2.0 0.053.

2.5...

Finding the Spring Constant]]>