Brain health/brain exercises?]]>

Also I need to choose between 3 different fans that has the following specs from the manufacturer:

120mm fan:...

Which fan/pipe combination is the most efficient?]]>

Find the mass of photon in motion.

E=hf

p=hf/c

I just started studying modern physics and am aware of the above two equations. However equating E to 1/2mv^2...

The mass of a photon in motion]]>

I enjoy, and sometimes find a real need, to consider the underlying...

Code, but not daVinci]]>

Why the Quantum | A Response to Wheeler's 1986 Paper

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...

Why the Quantum | A Response to Wheeler's 1986 Paper - Comments]]>

Practical Fluid Mechanics: inversions & mixing]]>

A runner moves with a velocity of 4.0 m/s due east for 5.0 minutes. The runner then rests for 30 seconds, turns around and heads due west with a velocity of 5.0 m/s for 5 minutes. What is the runner's average velocity for the...

Average Velocity]]>

How much time should I study?]]>

Given Kim's version of DCQE, let's say Bob in on earth looking at d0, Alice is on mars holding the prism that deflects the idler coming from (a) to d3 or (b) to d4. After the experiment run ends Bob should...

FTL communication via delayed choice measurement]]>

Question about Many Worlds branching in Quantum Mechanics]]>

(c) A heat exchanger is to be used to heat a process liquid within the tubes using saturated steam at 100oC. The tubes have an inside diameter of 20 mm and outside diameter of 22 mm. It is estimated that the inner surface heat...

A heat exchanger is to be used to heat a process liquid with...]]>

When I say students, I specifically mean the graduate and undergraduate students who do research under the professor. While I have never personally encountered such a thing, I've heard of...

How common is it for professors to yell at their students?]]>

Please critique:

We want to read file 'FileName' into SAS for some...

Inputting Data into SAS]]>

Could you please explain the matter so that I can understand the concept well?]]>

Hello. I'm stuck on some question, will glad if you can give me a little hint.

The problem is this:

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A charge -q is located at the distance 's' above a plane, which charged in a positive charge...

Changing Acceleration in an Electromagnetics question]]>

In coordinate bond, why doesn't the H^+ atom get a negative charge?]]>

we are organizing a regatta, there are 12 competing crews and we have six boats. Therefore the regatta is organized in so-called fleets, each consisting of two races at which six crews (using the six available boats) are participating. We assume to be able to race 10 to 15 fleets...

Mixing of regatta competitors]]>

Is string theory a deterministic hidden variable theory?]]>

Typically, practitioners of science treat the concerns raised by these disciplines in a very defensive manner. I don't mean to use "Philosophy" and "Sociology" interchangeably here, although that wouldn't be entirely wrong.

In short, I'm really only interested in...

Anybody interested in the Philosophy / Sociology of Science?]]>

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Volue of a sphere: ##~\displaystyle V=\frac{4}{3}\pi r^3##

Area of a sphere: ##~\displaystyle A=4\pi r^2##

Minimum/Maximum occurs when the first derivative=0

Finding the ratio of the volumes of a cube and a sphere]]>

Jumping to engineering]]>

I checked the currents that passed through several LEDs for

LEDs in parallel don't consume the sum of individual currents?]]>

Could someone please help me in understanding how the air is thrust rearward by a propeller?

I am specifically interested in how an axial-flow compressor, which uses aerofoil shaped blades to force the air through the engine does so, however I feel a good start is a propeller.

It makes...

Propeller - Rearward flow of air]]>

2. v^2 - u^2 = 2as

3. s = ut + 1/2 at^2

These three formulas are applicable when a is constant. Now my question is 'what does it mean by 'when a is constant'? Could you please explain it?]]>

The gas enters the tank at 10gpm. The entrance has a diameter of 1.5" and the vent has a...

Air Displacement Pressure]]>

Sketch, on a set of common axes, waveforms to represent the transient

response of circuits having transfer functions with the following parameters:

a) ζ = 0.5, ω = 1×10^3 rad s^-1

b) ζ = 0.2, ω = 2×10^3 rad s^-1

c) ζ = 2, ω =...

Sketch the waveform to represent the transient response]]>

Why can't we take 'k' as some other value?

I will be thankful for help!]]>

So this is not homework or an assignment, but usually my questions get moved here anyway. This is from a project I'm working on for my job. A user can choose between DPDT functionality (so having "SensorI" be a doorway that goes up...

Replacing two corresponding switches as one with AND-gates]]>

Turns out that Zoobyshoe beat me in posting about this in another thread, so he will officially be known...

Weird News Compilation]]>

I have decided that no matter how many times I ask, people will always leave my bedroom door open. Therefore, I have decided to try my hand at a DYI project to create an automatic door closer. I'm aware these already exist but I'm also doing this because I've always been interested in...

Need help choosing the necessary motor for my first ever DIY project]]>

Any tips before I spot weld it?]]>

For a project, I am trying to estimate the absorption curve of a certain plant species. Due to the variability within the species, I have taken the average of several measurements.

In the figure below, the blue curves represent...

Error bar calculation (statistics)]]>

Hi everyone]]>

Hi all, I have an issue understanding a statement I read in my text.

It first states the following Proposition (Let's call it Proposition A):

The number of unordered samples of ##r## objects selected from ##n## objects without...

Probability Theory: Multinomial coefficients]]>

Are all wavelengths of light possible?]]>

##\ \ \ \ \ ## In ##K##, an isolated rod

Momentum calculation of a rotating rod (part 2)]]>

A free Modern Introduction to Astronomy textbook]]>

Various Pressures in mass transfer]]>

- having mass

- rotating with angular velocity

- moving along the direction of its symmetry axis...

Formulating the kinetic energy of an object - helical motion]]>

Mass transfer and absorption]]>

On the benefits of retaking advanced linear algebra]]>

A researcher studied six independently assorting genes

in a plant. Each gene has a dominant and a recessive allele:

R black stem, r red stem; D tall plant, d dwarf plant; C full

pods, c constricted pods; O round fruit, o oval...

Genetics Problem 1]]>

Can electrons absorb a photon?]]>

Measurement vs. Interaction]]>

For me this is one of the biggest mysteries ever, why we don't detect more massive or less massive electrons?

Is it related...

Why are all particles of the same type identical?]]>

In a inertial system, the invariable mass of a system never change with time. This system may not be an isolated system.

Whether in any inertial system, the invariant mass of the system remains unchanged.

Or, in a certain inertial system, what is the necessary...

A question about invariant mass]]>

i just want to tell, can somebody, who have time just to read this file, you understand direct, if you know about fm detection, i just dont know how to make a transformer in ltspice, can somebody told how to make it this circuit with transformer and tuned please]]>

Here are the conditions:

1. The red-line is the hydraulic cylinder with "X" as the fix point.

2. The hydraulic cylinder will stroke out from...

RTG crane -- hydraulic motor and linkage design to turn these wheels]]>

k

Standard boost, particles with mass M > 0]]>

Undergoing major personality changes in early adulthood - how common?]]>

Here is the PDE and Lax-Wendfroff scheme, assume initial conditions are given:

$$u=\text{function of x,t}\\\hat{u}=\frac{1}{\Delta x}\int_{x_{i-1/2}}^{x_{i+1/2}}u\thinspace dx \text{ (the average flux...

Derivation of Lax-Wendroff finite volume scheme]]>

Say I am already travelling at velocity "v" where "v" is approaching the speed of light. I...

Help with constant acceleration under special relativity]]>

Suppose there is an electric balance that reads 5.67g

The limit of reading is 0.01g

The greatest possible error is half of the limit of reading and is thus 0.005g

By this logic, and assuming the very best possible situation, I...

Greatest Possible Uncertainty and Sig Figs]]>

I think

## \frac{d}{dx} ( \hat{A}f(x) ) = \frac{d}{dx} f(-x) ##

## \hat{A} \frac{d}{dx}f(x) + f(x) \frac{d}{dx} \hat{A} = -\frac{d}{dx} f(x)##

## \hat{A} \frac{d}{dx}f(x) + \frac{d}{dx} f(x) = -f(x) \frac{d}{dx} \hat{A}##

##...

How to find eigenvalues and eigenfunction]]>

What's Known about the Wave Function and Gravity]]>

##\textbf{1)}##

My current understanding is that unlike Einstein's model, he views a 1D solid as a chain of atoms similar not unlike a 1D chain of masses coupled with springs. Thus a chain...

Questions on Debye's Model of solids]]>

See this on mosfet:

IRF3205

P705D

KCAB

Here is photo:

https://plus.google.com/photos/photo/103754471497291178620/6538401194800693618...

Mosfet replacement]]>

but why do weird things like 3:5 Jupiter/Saturn stuff happen?

Or doesn't it?]]>

]]>

Rotating rod with two masses]]>

I can't understand why friction acts radially inwards when a body is rotating on a rough turntable. If the friction is removed, the body would move tangentially, hence it has slipping tendency tangential, not radially outwards,...

Direction of friction in circular motion]]>

Space Stuff and Launch Info]]>

I have always had an issue with understanding the definitions used in mathematics. I need examples before I can start using and reasoning with them. However, with tensor products, I have been completely stuck.

Stillwell's Elements of Algebra was that made abstract algebra "click" for me....

Motivating definitions from differential geometry]]>

This ultimately should lead to ##\mathcal{Im}[A+B+Te^{2ip}]=0 ## upto a sign (perhaps if I didn't do a mistake).

There is a condition on ##R ## that it is real,...

Verifying an equality]]>

However, it is also...

Why is it said that magnetism breaks time reversal symmetry?]]>

I have a problem with the rotary lobe pump, it causes a very loud noise when running. The pump specs are as follows:

Liquid: Syrup (The liquid is in the 15,000 liters tank.)

Viscosity: 2200 cPs

Temp: Ambient

Flowrate: 15 m3/hr

Discharge pressure: less than 2 bar (open ended pipe)

Inlet...

PD pump (Rotary lobe pump) -- loud noise]]>

Here is the last page of part 5.

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

Meaning of Wave Function Collapse]]>

Two identical insulating balls of mass m hang from massless strings of length l and carry identical electric charges, q. you may assume that the angle of separation θ is so small that tanθ ≅sinθ≅θ.

View attachment 229579 ...

Seperation between two charged ball]]>

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I proved part a)

Can you please check if part b) is correct?

I don't know...

R-C circuit]]>

When the nucleus is coupling to the

photon we call it an

Gamma Decay (Electric and Magnetic Transitions)]]>

I am using IBM-BPM tool, and I am trying to do the custom loggin]]>

I'm stuck on part (b) and (c) of the following question

View attachment 229568

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The partition function was ##Z_N...

Statistical physics question - particles in a magnetic field]]>

If ##a \neq 0##, evaluate the integral

$$\int \frac {dx} {a~\sin^2~x + b~\sin~x~\cos~x + c~\cos^2~x}$$

(Hint: Make the substitution ##u = \tan x## and consider separately the cases where

##b^2 - 4ac## is positive, zero, or...

Integral of 1/(a sin^2 x + b sin x cos x + c cos^2 x)]]>

All without any error bars.

It got me thinking, what's the history of error bars in scientific...

History of Error Bars in Physics]]>

What's the difference between neutral and stable?]]>

However, some of these powerlinea go long distances, and I’m trying to figure out how the electricity alternates...

Alternating energy]]>

Either the Sun Is Getting Smaller or Gravity Is Getting Weaker

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...

Either the Sun Is Getting Smaller or Gravity Is Getting Weaker]]>

What Determines Whether Radiation Passes Through Materials?]]>

Is there a natural process that...

Caesalpinia seeds]]>

What problems would 'black holes' not being formed solve?]]>

How to keep the components of a metric tensor constant?]]>

Advice on Extra Math Classes for Physics Degree]]>

Is there a way to increase the efficiency of spdc?]]>

a^(logₘn)=n^(logₘa)

Would you still see the same pattern on the screen?

Would it affect the wave function...

Particle goes through a double slit + decays, what happens?]]>

"

Ph. D. - worthwhile?]]>

Transient capacitance]]>