I do get why polar molecules can form bonds, which is due to the e- arrangement,...

Why are non-polar molecules attracted to each other?]]>

Thus, we see that K is analogous to 1/C , which makes sense, because with a given current for a given time, a smaller capacitor will build up...

Why a smaller spring will build up less force?]]>

A plank of wood sits on top of two rollers with radius of 44.4 cm. The plank is pulled forward so it moves at a constant acceleration of 2.24 m/s^2, starting from rest, and the rollers roll without slipping along the ground...

Angular Speed of Rollers]]>

Curl in cylindrical coordinates]]>

Code (C):

Simple calculator]]>A few years ago I heard about a list named the "10 characteristic experiences of physics", may I know if a such list exist?

A few years ago, at the physics workshops at the Palais de la découverte, I saw the so-called "triple point of water" experience.

The experimenter told us that...

A list named the"10 characteristic experiences of physics" does it exist?]]>

Visual effect in special relativity.]]>

Let us think of infinitesimal vacuum volume [tex]dr\ sin\theta d\theta d\phi[/tex] around the star in center.

Light emitted from the star hit the bottom surface, r, of the volume. Say violet light photons hit the area 1...

Conservation of energy in GR]]>

- When replying to a thread, the LaTeX and BBCode help page links are displayed below the text box. These should be displayed in the Create Thread page as well, because I find many new members not knowing about mathjax....

Suggestions related to Mathjax]]>

A Simplified Synthesis of Financial Options Pricing

View attachment 229473

...

A Simplified Synthesis of Financial Options Pricing - Comments]]>

Suppose a particle of mass

Path of a deflected charge? Solvable ODE's?]]>

"Prove that ##\sum_{n=0}^\infty s^n e^{-\lambda} \frac{\lambda^n}{n!}\sum_{m=0}^\infty s^m e^{-\mu}\frac{\mu^m}{m!}=\sum_{m+n=0}^\infty s^{n+m} e^{-(\lambda+\mu)} \frac{(\lambda + \mu)^{m+n}}{(m+n)}!##

Need help simplifying a summation with binomials.]]>

Trouble with high frequency astable multivibrator.]]>

View attachment 232549 View attachment 232550

View attachment 232549 I'm supposed to find the normal force acting on the box by the slab as a function of time. The problem is I don't know what the constraint is. I...

Lagrangian Mechanics with one constraint]]>

synchronizing two devices with RF signal]]>

I'm solving a problem using tuple relational calculus ( TRC) in DBMS.

Problem

Find the name of all the employees who work for XYZ Bank Corporation.

...

tuple relational calculus in dbms]]>

Something I don't understand about a simple tension problem]]>

-x^3 - 6x^2 -12x -8

I don't know, I just know the roots are -2 with multiplicity 3.]]>

Given this following circuit:

View attachment 232541

What is the internal resistance of the meter movement ( R_I).

This is part of a project I'm doing and I know the equation that gives you the internal resistance in...

Finding Internal Resistance through Circuit Analysis]]>

Combination Circuit Help (pic)]]>

Conservation of Angular Momentum on a rotating disc]]>

A mass m1 is located on a platform with mass M. The platfrom is located on springs with total constant k such that it can swing vertically in direction x.

a) Write down the equations of motion assuming mass m1 will always be...

Equation of oscillating system without any starting values]]>

Electrical Design Case Studies]]>

2. I recently encountered a book Aleksandrov, Kolmogorov, Lavrentev "Mathematics: its...

A book for fast introduction to modern math?]]>

H(ω-ω

I thank you for reading this question.

If given as is, is this a valid question? I ask because, without context, I reckon there could be multiple answers to it.

Your...

Is this a valid question?]]>

I work for a small seed oil extraction plant where we cold press the seed then solvent extract the residual oil from the presscake. In the solvent extraction plant we use liquid ring pumps to pull the required vacuums. The Plant Vac Pump (PVP) is used in all...

Excess Heat Generated By a Liquid Ring Pump]]>

I know it's a strange question. Here is Alexa's answer:

https://drive.google.com/open?id=1hXYFT_zBnFy-N0BotiTSDL8_S6nHK3ns]]>

The position of a participle in a fixed inertial frame of reference is given by the vector

r = i(x

where x

a) Show that the particle moves in a circle...

Position of particle in inertial reference frame]]>

So, I know that there are distant galaxies that are being carried by the expansion of space faster than the speed of light relative to us. But were these objects actually receding >c when the light we are seeing was...

Do we directly observe redshifted galaxies receding >c?]]>

I originally decided to be a physicist when I took an online course in Astronomy which talked about the greatest unsolved mysteries of the universe. After coming to university and conducting research in Particle Physics, I think I like it better and would pursue it instead....

How do you reconcile performance and curiosity?]]>

A person stands on a bathroom scale in a motionless elevator. When the elevator begins to move, the scale briefly reads 1.05 times the persons regular weight. Calculate the magnitude and direction of the acceleration of the...

How to find acceleration using multiple of weight only]]>

Large logarithms and RG]]>

Given two things spherical shells radii r1 and r2 with r2 > r1.

The inner she'll is charged uniformly with a total charge Q1, while the outer shell with Q2.

A) use gauss law to computer the electric field everywhere

B) Use any...

Electricity and magnetism (Gauss' law)]]>

Any bio-related benefit of UV radiation?]]>

This is for a lab report and I am just confused about how I should regard volume because this issue is affecting 3 other questions. If you heat a gas in a closed flask that is connected to a manometer with water in it, the water...

Confused about the volume of a rigid (glass) container]]>

Diodes in pairs]]>

View attachment 232307

y

I...

Hydraulics help please -- Energy loss in a long pipeline]]>

Below

MgΔY=1/2 mΔv^2

Vf^2=Vi^2+2gx1

For question 49, I used the first equation, and the result is Δv^2=2gY. Then, solving...

Determine the distance the object travels.]]>

In the file below.

Speed= total distance over total time.

Acceleration = change of speed over time

I tought it is just E because of the first rule above. But...

Calculate the average speed.]]>

$$d=\log_{10}\left(\frac{I_{0}}{I_{t}}\right), \tag{1}$$

where ##I_0## is the light intensity incident on the material and ##I_t## is the transmitted intensity (so that ##I_t/I_0## represents the fraction transmitted).

Many lasers don't...

Absorbance of a finite waveband]]>

Suppose you have a flat panel mounted on a wall, and a very strong magnet that will move in any direction on the plane of the flat panel. Through any possible arrangement...

Charging a battery by moving a magnet randomly in 2D plane?]]>

I am in India and studying UK education system (IGCSE). So, I didn't take physics as a subject and now I am regretting it because it's too late. Can I do a degree in physics even if I don't have it? I have pretty good knowledge about the...

I don't have physics, what can I do?]]>

Solar Spectrum: Continuous & Absorption Confusion]]>

There are two components A & B both travelling the same direction but at a different velocity. I can find out the exact velocity of both the components when they just hit each other, thus relative velocity is known.

Is there a way I find out the force...

Relative velocity and force relationship]]>

The lab: Centripetal Force Lab

a Rubber stopper is moving in a horizontal circle at a constant radius and it is attached to a string where at the bottom, there is a mass where the mass is 100g, 150g, 200g, 250, and 300g (can see...

Centripetal Lab- finding the mass from the slope]]>

Here is my objective. I want to lunch a golf ball about 10 or so feet.

I know that I need to...

What is the Mass of a Piston?]]>

How to like chemstry? [Looking for inspiration]]]>

A ferry boat is crossing a river that is 8.5 x 10^2 m wide.

The average velocity of the water relative to the shore is 3.8 m/s E and the average velocity of the boat relative to the water is 4.9 m/s S.

How long does it take for...

A ferry boat is crossing a river that is 8.5 x 10^2 m wide.]]>

Question Regarding Continuity]]>

I am looking to utilise some simulation results in conjunction with applied research on these materials. The focus is really the applied stuff, and I have very little background in...

DFT modelling of graphene, fullerenes, nanotubes etc]]>

https://en.wikipedia.org/wiki/Rayleigh_scattering]]>

In the attached file..

The question asks about the charge and capacitance after being separated by twice the original separation. I also need to know if it is kept connected to the battery( spearted to twice the distance,too) ,...

What would happen to the charge and capacitance?]]>

A photon of wavelength 300nm is emitted from an atom when an electron makes a transition from an energy state of -4 eV to a state of -8 eV. IF the initial state had been at enerygy of -6 eV, the wavelength of the photon emitted...

Calculate the wavelength when electron transits.]]>

The table below shows some kinetics values for two types of the GOD enzyme, the free and the immobilised.

View attachment 232538

How can I comprehend what these values mean?

I want to know how many grams of substrate are 'converted' per sec per mg of enzyme.

I assume the substrate...

How to calculate kinetics values?]]>

[tex] <\phi_m, \phi_n> = (2/l) \int_0^l sin(m-1/2)(\pi x/l) sin(n-1/2)(\pi x/l)\, dx

\\ = 1/l \int_0^l...

Show that set is an orthonormal set in PC(0,l)]]>

Setup:

There is some long current-carrying wire. Outside of that wire, there is some test charge.

In the first situation, the test charge is...

Relativity and Electromagnetism]]>

- epigenetic tags/factor compounds are coded by genes? Or are they "external" compounds?

- are epigenetic factors/tags usually monomers? Or can they be polymers?

- Is there a comprehensive list somewhere of all epigenetic tags/factors?

(I have been attempting to...

Epigenetic tags/factors]]>

Accumulation

Depletion

Inversion

For P substrate the surface potential increases as I increase the gate voltage (positive). The books say that at Vg = threshold voltage the surface potential is maximum. But why does it...

For MOSCAP why is surface potential constant after Vg = Vth]]>

Self-interference in double-slit experiments]]>

I don't really see these two terms used together in articles that I come across. I just wanted to confirm whether they are in fact, directly linked?

Since hemoglobin gene is expressed only in red blood cells, this would make this gene a...

Luxury genes and epigenetics]]>

I'm making a ball cyclotron (https://rimstar.org/science_electronics_projects/ball_cyclotron_electrostatic_accelerator.htm) for a school project. To generate enough voltage, I'm using a Van der Graaf-generator. The...

ball cyclotron]]>

I've tried hours and hours to model this problem but i didn't succeed. Can you help me ?

profitability index pi is known, which expresses the...

Stuck with an Integer Programming problem]]>

Why must the subgroup ##N## be finite? Isn't this result true for subgroups of any size?]]>

A projectile is launched at an angle of 60° from the horizontal and lands 99 s later at the same height from which it was launched.

1) What is the initial speed of the projectile (in m/s)?

I already figured this out to be...

Calculate the displacement? (Projectile motion problem)]]>

Selection versus genetic drift]]>

The...

Clocks in SR]]>

What are the best references for neurogenesis?]]>

View attachment 232435

##\hat{P}= -ih d/dx##

To actually obtain ##\psi_{p_0}## I guess one can apply the momentum operator on the spatial wavefunction....

Eigenfunction of momentum and operators]]>

While learning to drive, you are in a

Uniform Circular Motion question]]>

Ladder operators and SU(2) representation]]>

I have been wondering about the validity of Maxwell's equations in quantum physics. I looked in the internet and it seems from what I understood that: Maxwell's equations are valid for any situation, classical or quantum. In fact, maybe it holds more legitimacy than Schroedinger...

Maxwell's equations and QFT]]>

Two retailers compete on price in a market. Firm 1’s demand depends on both its own price and firm 2’s price as follows: q1 = b – p1 + ap2. Similarly, firm 2’s demand depends on its own price and firm 1’s price: q2 = b – p2 +...

Cournot Model in a Duopoly Market]]>

In this problem, we'll construct the ##(\frac{1}{2},\frac{1}{2})## representation which acts on "bi-spinors" ##V_{\alpha\dot{\alpha}}## with ##\alpha=1,2## and ##\dot{\alpha}=1,2##. It is convential, and convenient, to define...

Vector representation of Lorentz group]]>

Consider the operator ##F_a(\hat{X}) =e^{ia \hat{p} / \hbar} \cdot F(\hat{X}) e^{-ia \hat{p} / \hbar}## where a is real.

Show that ##\frac{d}{d_a} F_a(\hat{X}) \cdot \psi = F'(x) \psi## evaluated at a=0.

And what is the...

Operator relations]]>

Also if my goal was to attract an object, would it make more sense to have two thinner...

Electromagnets, is thinner wire better? Quantity?]]>

Before I post my question, let me admit that my foundation on mathematics is poor. I am trying to work on it, specifically on the application part.

When I came through the following image, I was stuck to understand why I will need one like Taylor's series in a simple case like "F+ΔF = F...

Mathematical series in physics - Why and when do we need them?]]>

This week, our theme as at least one point to make. The main subject of your photo must have at least one pointed sharp end or tip. How sharp it comes to is certainly relative, but it must look as if it comes to a point.

Examples are pencils,...

PF Photo Contest - Make A Point (10/20-10/26)]]>

Is trying to go into fusion realistic at this point?]]>

Those who say “no” seem to regard PLA as merely a neat way of packaging the equations. Those who say “yes” seem to regard PLA as somehow fundamental. (There have actually been two recent books on this,...

Does the Principle of Least Action Have a Physical Meaning?]]>

Stats Question Help]]>

So at the first level, it seems a particle based view of quantum field theory is difficult...

Structure of Matter in Quantum Field Theory]]>

In an EPR experiment...

Does the EPR experiment imply QM is incomplete?]]>

ok this is not a homework but i am confused by the derivation of ## f = \nabla (m . B)##

both start out with ##\vec B(r) \approx \vec B_0 + (\vec r' . \nabla)\vec B|_0 ... \\

f = \iiint_{v'} \vec J( r') \times (\vec r' ....

Confusion in the derivation of the force on a magnetic dipole]]>

g (log 1/2) = log 1/512

g (-,3) = -2.7

So she had an Indian relative back 9 generations

But suppose the DNA shows 1/689 * Indian .00145, log = -2.83

then: g (-.3 ) = -2.83

and she has Indian relative(s) going back , g = 9.46 generations.

How is that...

Sen. Warren 1/512 U.S. Indian]]>

Hi everyone!]]>

Consider a classic wedge and block system, (block on top of wedge(inclination theta)). there is friction between the block and wedge (not enough to prevent block from sliding). All other surfaces are smooth. For the motion that...

conditions for conservation of momentum]]>

Prove that $$\bf{ a \times ( b \times c ) = \phi [ b(a \bullet c) - c(a \bullet b) ]} $$

for some constant phi

So I have used the unit vectors i, j, and k and...

Vectors: How to prove the BAC-CAB identity w/o components?]]>

Lets say I have a list of numbers.

income=[17000, 11000, 23000, 19999, 21000, 10000]

I sort them income_sorted=[10000, 11000, 17000, 19999, 21000, 23000]

Calculate med 2nd Quartile.

Median vs. Second Quartile question]]>

Prove that ##\forall n \in \mathbb{N}##

$$\frac{n}{2} < 1 + \frac{1}{2} + \frac{1}{3} + \ldots + \frac{1}{2^n - 1} \leq n \text{ .}$$

Peano axioms and field axioms for real numbers.

Proof of an inequality with natural numbers]]>

A black and yellow body at room temperature are thrown into a furnace at very high temperature. How will the initial and final brightness of both compare?

λT=constant

Brightness change with temperature]]>

Best anode materials for water-based hydrogen generator?]]>

Geometric Optics Approximation - validity]]>