Let ##R## be the ring of all continuous real-valued functions ##f : [0,1] \to \mathbb{R}## with pointwise addition and pointwise multiplication of functions as its two operations. Let ##c \in [0,1]## and denote ##M_c = \{f\in R...

Ring of continuous real-valued functions]]>

+C ?<--- -3/2 C --->? -C

+ q

X----------------------------o-----------------------------X

P(midpoint)...

Three Charges Aligned on a Straight Wire]]>

I have a question regarding the attenuation properties of Faraday cages. More specifically, I'm looking for a generalization I can use to better understand how thick they should be for a given frequency. I did a small experiment by taking a small enclosed aluminum box and placed an...

Faraday cage attenuation]]>

Please could somebody verify if what I have understood about the UV catastrophe is along the correct lines. I used this hyperphysics link:

(http://hyperphysics.phy-astr.gsu.edu/hbase/mod6.html)

Is it saying that using classical physics an object like a pen should be emitting...

Ultraviolet Catastrophe & the Photoelectric Effect]]>

A mass ##M## is accelerated by a spring of length ##L##, wave-speed ##v_p##, spring-constant ##K## and a constant force ##F## at the other end. As ##K## increases, the extension of the spring ##dx## decreases as does the...

Acceleration of mass depends upon K and L of spring?]]>

Here is what I know about fluids flowing: You have a pressure difference between the two ends of the pipe. This causes a net force acting on the left side of the fluid in the pipe. Therefore, this incompressible fluid flows from left to...

How does the pressure drop as a fluid flows through a pipe]]>

https://www.amazon.com/resqme-Origi...437&sr=8-5&keywords=automobile+window+breaker

What if your windows were tinted with UV film. Would it still be effective?

Are...

How effective is a pocket car window breaker?]]>

Improper integral with substitution]]>

Telescope recommendations for watching a galaxy?]]>

Does galaxy formation conserve mass and angular momentum?]]>

Let ##G## be a finite p-group and ##Z(G)## its center. If ##N \not = \{e\}## is a normal subgroup of ##G##, prove that ##N\cap Z(G) \not = \{e\}##.

Since ##N##...

Using class equation to show that intersection is nontrivial]]>

Radio Frequency Acceleration in Particle Accelerators]]>

Math Challenge - December 2018]]>

Beyond Viscous Drag, Cavitation, Laminar Flow, & Reynolds]]>

View attachment 235580

Any suggestions?]]>

If a is a real number, then a^2 is positive

The book gives me two propositions:

1- if a,b are positive, so are the product ab and the sum a+b

2- if a is a real number, then either a is positive, a...

a^2 will always be positive]]>

I can easily calculate the angular momentum L,...

Combining angular momentums]]>

It's my...

Reconciling an apparent contradiction about Parallel Circuits]]>

View attachment 235516

Long-range beam-beam interactions]]>

When bullets are shot on Superman, they bounce off of his chest. 100 Bullets will be shot on his chest per minute, each with a mass of 9g and v= 1000m/s. Assume that the bullets will bounce off elastically back in x-direction....

Shooting bullets, work & power]]>

Basic Physics Questions]]>

Demystifying the Often Misunderstood Bernoulli's Equation

View attachment 235151

...

Demystifying the Often Misunderstood Bernoulli's Equation - Comments]]>

Here is the diagram I am referring to, figure 27.-9:...

Calculating the resolution limit using Fermat's principle]]>

This report from DCO is a kind of review article. This article itself does not have specific reference papers cited. Just another review article. I think the DCO people expect us to dig around a little. Plus there...

Deep Carbon Observatory report]]>

There was an Italian movie, shot is sixties or seventies, kind of a psychological drama (definitely not an action movie) that ended with a long car crash scene: guy was speeding through the country, at crossroads something went wrong, his car started rolling and...

Trying to remember an Italian movie]]>

Calculating the number of energy states using momentum space]]>

Best multiple/many individual MOSFET driver IC?]]>

I hope this is the correct forum section to post this in.

I heard about this problem from a youtube video but I've not been able to simulate it because the video was meant only for an introduction into PID control.

Here's the problem:

A remote control helicopter is hovering just...

Transfer Function relating momentum and force]]>

I try to integral as picture 1.

The result that is found by me, it doesn't satisfy Green's function for boundary value problem.

show in picture 2 & picture 3.]]>

View attachment 235577

The op amp has a near ideal level 1 model with G = 5000V/V, ri = inf, ro = 0

How would I obtain the feedback function?

I know I have to find the feedback function which...

What is the gain error for this op amp driven by the voltage]]>

For this question I want to clarify that 5k which is the electric field component perpendicular to the incident plane ( the xy plane) will be continous for reflection and refraction ,

For which none of the options seems correct ,am I right??

The component of magnetic...

Reflection of an EM wave]]>

View attachment 235409

Z = √(X

X

X

I = V/Z

First off, thank...

Finals Study Time! A Two Source Circuit w/Inductor, Cap, and Resistor]]>

Let ##a,b## be squarefree integers and set ##R = \mathbb{Z}[\sqrt{a}]## and ##S = \mathbb{Z}[\sqrt{b}]##. Prove that

a) There is an isomorphism of abelian groups ##(R,+) \cong (S,+)##.

b) There is an isomorphism of rings...

Showing when quadratic integer rings are isomorphic]]>

I'm wondering if it would be theoretically possible to build a completely new city over a...

Sci-fi author needs advice on building a multi-layered city]]>

Mortal Engines movie - Wired magazine looks at the science]]>

View attachment 235540

For this problem I have calculated the average force as ∫ Fdt/ ∫dt

And using a(acceleration)=2h(height)/t

Average force during a ball's elastic bounce off of a plate]]>

I am revising on the derivation of the differential equation of energy (White's Fluid Mechanics 7th ed) and I'm having trouble understanding the sign convention used in the viscous work term.

View attachment 235526

The textbook...

[Fluid Mechanics] Negative sign on the viscous work term]]>

(I forgot to add the arrow on the diode and i'm too lazy to fix it. And I just realized that the resistor is wrongly placed.)]]>

Maybe an example would be two clarinets...

Sound of 2 identical horns cancels out?]]>

There has been a Physics Prize every year except 1991 and 1994.]]>

The story according to her:

Slowly approaching a stop sign. No busy traffic. No trees/animals in sight. Few people. Suddenly, the rear windshield cracked with a loud boom...

Under what conditions can glass crack spontaneously?]]>

This is my first post and by no means a simple question, I believe. But all advice is appreciated. In particular, if there are university teachers/professors that are willing to give their opinion, I’d be very grateful. So thank you in advance.

Here’s a little background regarding my...

Tricky master's thesis problem]]>

undervalued. I have two valuations V1, V2 for each of the players, though in different "currencies" and I am trying to see how to express both in the same currency. I have been...

Classification/Valuation Problem: Baseball]]>

Rolling with slipping and condition for not slipping]]>

Questions about data wire shielding]]>

Am I looking at the right Physics textbook?]]>

A prize is hidden in 1 of 7 boxes and a person has to guess in which box it is.

He opens a box one after the other and I questioned myself what the probability might be for...

Opening boxes consecutively to find 1 prize]]>

Using the thermosyphon effect for a floor water heating system]]>

We have a coin with probability ##0\leqslant p \leqslant 1## of getting heads. We flip the coin until we get ##7## heads in a row. Let ##N_7## be the number of necessary flips to get the ##7## heads in a row.

What is the...

expected value for 7 heads in a row]]>

(

Most basic stability problems is introduced simply as a box with a load placed on its side. And you do the typical momentum calculation around...

Stability - calculations taken for granted in books]]>

Would it be possible to implement a "psychology" sub-forum?]]>

Standing Wave Fundamental Frequency and Particle Vibration.]]>

Let's hang out at

---------------->...

Inside the bar.]]>

A question about a popular example of expansion]]>

1) $${\displaystyle v=v^{i}e_{i}={\begin{bmatrix}e_{1}&e_{2}&\cdots &e_{n}\end{bmatrix}}{\begin{bmatrix}v^{1}\\v^{2}\\\vdots \\v^{n}\end{bmatrix}},\ \qquad...

Confusion about Einstein notation]]>

Is the inflationary universe a scientific theory?]]>

At first I would like to ask three questions.

1) A torus shaped resonant cavity, like the ones found in particle accelerators and klystrons, is it...

RF cavities and related devices]]>

Not having children to save money]]>

How much money can you make in physics?]]>

Can you measure a particle without breaking superposition?]]>

Thanks]]>

Probability that a Random String is a Word]]>

For this contest, the theme is the color blue. Your photo must have, as its dominant color, the color blue.

While there are variations to this color, and the possibility that different screens may display color slightly differently, please ensure that...

PF Photo Contest - Blue (12/8-12/14)]]>

Physicists and physics majors, was it worth it?]]>

Let's say the solution on the left hand side is a sinkx + b coskx = 0

We get one solution for each E if we omitted a and another solution if we omitted b. However, how to conclude that they are all the solutions? Will there be any solution of the 5 coefficients such...

Question about the solution of TISE (finite potential barrier)]]>

By using Elon Musk's Neuralink (Neural Lace 2039???) ,NerveGear, exo-skeletons, OpenWorld VR maybe?

And if we were to achieve this would anyone still want to live in the real world apart from people who are maintaining the system and...

How close are we to Deep Dive/Full Immersion VR?]]>

About spin precession in a magnetic field]]>

I'm somewhat new to the concept of completeness, but from what I understand, a particular basis function is complete in a given space if it can create any other function in that space. Is this correct?

I read that the set of polynomials is not complete (unsure of the space, since Taylor...

Completeness of a basis function]]>

My wife just drew this

View attachment 93241]]>

Are there issues with Conformal Gravity as a DM solution?]]>

Looking for intuition on differentials and arc length]]>

I am required to obtain the following

1) Energy targets and pinch temperatures

2) Composite Curves

3) Grand Composite Curve with and without utilities?

4) What utilities are you going to use to fulfill the energy targets? Why...

Process Simulation Project- Gothenburg Refinery]]>

Calculations on a fireworks rocket?]]>

Here is the last page of part 5.

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

A current of 50A flows through a copper wire of diameter 0.5 * 10

A)4*10

Magnetic Induction]]>

First, I want to thank ahead of time any help that can be provided. Second, I'm just an advanced tinker'r needing help on a project.

-Lever 1 and Clamp are attached

-Lever 2 and Rod 2 are attached.

-Clamp is tightened around Rod 2

-Upward force on end of Lever 2...

Calculating if a Pipe Clamp will slip]]>

What have you used that can even apply in Antarctica or in the mountain tops?

I want to...

Coat Insulation Selection for the Snow and Mountaineering]]>

Taylor first writes down the change in the momentum of the rocket as dP = P(t + dt) - P(t) = (m + dm)(v + dv) - mv =...

How to develop the rocket equation]]>

Given ##y''+\lambda^2y=0## and BCs ##y'(0)=y'(1) = 0## we know eigenfunctions are ##y=\cos (n\pi x)##, and for ##n=1## this implies there is one zero on the interval ##x\in(0,1)##. However, I read that for SL problems, the ##jth## eigenfunction has exactly ##j-1## zeros on ##x\in(0,1)##,...

Sturm-Liouville Eigenfunctions]]>

I am currently involved in research that seeks to utilized a Walker Scientific power supply and magnetic. The system is old but functional. We seek to utilize the magnet in order to conduct some low temperature experiments. We need information on this power supply, of...

Remote control of a Walker Scientific Magnet & Power Supply]]>

View attachment 235218

I'm wondering if it just might be a faulty connection.

Should I try to...

Computer screen garbling text]]>

Advice needed on the best way to learn smart phone]]>

Parameterize the part of the curve which allows an equilateral triangle, with the height 3R, to roll from one vertex to the next one, while its center travels at a constant height.

I will include...

Finding the parametric equation of a curve]]>

The following pedigree shows that the trait is autosomal recessive. The probability of carriers in the population is 1/3. What is the probability that the child of III-3 and 4 is affected?

View attachment 235436

What is the probability that the child is affected?]]>

How does a digital multimeter measure conductance?]]>

Wanting to go to a good graduate school in the US]]>

The operating cost of a truck is 12+(x/6) per km, when the truck travels x km/hr. If the driver earns 6 rupees (*or whatever currency your country has) per hour, what is the most economic speed to operate the truck on a 400 km...

The minimum of a function in a given domain]]>