However, the temperature of planetary surfaces without an atmosphere are often quoted. For example, the temperature of the lunar surface ranges from about -200 F to +200 F depending on whether or not the surface is exposed to the sun or is in shadow....

Temperature of Space]]>

How can we define a space?]]>

i understand that the short branch has no resistance other than the wire itself which means it has super small resistance and by ohm's law I = V/R where the voltage is divided by a super small value means the...

Why is there no current in a parallel branch of a short.]]>

Thanks]]>

How does the charge field document this?

Does the field recognize both components? Only one? And once the field is detected, defining which path was taken, does the field alter it's nature through...

Where is the field?]]>

Mentor Changes Dec #2]]>

Blackbody Radiation]]>

View attachment 110294

The ideal fluid moves at constant speed along the horizontal pipe. Because the fluid is ideal...

Pressure in piezometers with ideal fluid]]>

\begin{equation}

G=\begin{matrix}

(1-g^2) &0& 0& 0&\\

0& (1+f^2)& (-g^2-f^2)& 0 \\

0 &(-g^2-f^2)& (1+f^2)& 0 &\\

0& 0& 0& (1-g^2)

\end{matrix}

\end{equation}

It's a matrix that's in a research paper (which I dont have) which gives...

Normalization of 4x4 matrix]]>

Problem: Ball rounding a corner that can move]]>

I plan on wiring an emergency flashlight to power an led. It must be able to store charge without batteries, generate charge and create a light.

None, at least for now

How to wire an emergency flashlight?]]>

With this set up Internet has slowed down for me for a while now. Videos stop and go, so does old Flash games that I used to play correctly before. The websites take a relatively...

Why is my old browser faster than newer versions?]]>

View attachment 216561

The energy stored in the capacitor is ## \frac { CV^2 } { 2 }##. So, this much energy will dissipate as heat. Hence, the correct...

The energy lost in discharging a capacitor]]>

I'm looking for functions that would qualify as

Specifically, given a real-valued vector space V of...

Measures of Linear Independence?]]>

Which physics class should I take first?]]>

In thermodynamics, we say: the amount of energy Q, can raise temperature of the liquid by the formula Q1=cm(t2-t1); when the liquid reaches the boiling point (100 C), we write Q2=Lm.

Q2 is entirely spent on changing liquid state...

Liquid boiling and Evaporation]]>

Building on QP from 5 reasonable axioms]]>

Pressure Equalization -- speed and time of duration]]>

taking iron from iron]]>

Numerically solve EFE for the solar...

Deciding on senior thesis project]]>

Find the ∆S per mol between liquid water at -5 ºC and ice at -5ºC at 1020hPa

Data:

∆CP,m fusion = 37,3 J K-1 mol-1

∆fusH = 6,01 kJ mol-1

The answer is 21.3 J/K mol

Usually I solve these problems...

How do I find the entropy variation?]]>

help identify a bacteria]]>

An object of mass m is rotating, hanging from a string of known length

Circular Motion - Hanging object swinging around]]>

Relative phase measurements]]>

Heat vs agitation]]>

there is a whole website to make people understand it i read the articles and i didn't found any thing complicated

knowing the i am 13 so it should be very hard to understand]]>

However...

Coordinate singularity at Schwarzschild radius]]>

My T-shirt and the Standard Model]]>

Intro to Analysis, Intro to Real Analysis I, and Numerical Analysis

Thank you,

Tracie]]>

Is it nebulosity or an artefact?]]>

First year physics book]]>

I am reviewing some of my tests for a final, and having previously re-read my forces chapter, I thought that angles rising...

Proper usage of trig functions in force problems]]>

A round bar .125mm in diameter , is to be used as a beam. IF Youngs modulus For the material E=200x10

A) Maximum allowable bending...

Bending Moment]]>

A rectangular Cross-section beam, 20cm deep by 10cm wide, is subjected to a maximum bending moment of 360kNm

A) Calculate the second moment of area of the beam cross-section

B) what is the maximum stress in the beam under this...

Torsion and stress on a beam question]]>

The usual official requirement is three semesters of Calculus, and then one more combination course which combines some linear algebra and not-too-complicated differential equations. Often the Physics majors, at least for...

What should the Mathematics requirements be for a Physics degree]]>

A solid sphere is cut in half and a homogeneous hemisphere of radius r and mass M is set upon a table(with its flat side up). The surface of the table is perfectly rough. The hemisphere rocks back and forth with small amplitude...

The length of a pendulum that is equivalent to a rocking hemisphere]]>

Need help with a thought experiment about a Faraday generator]]>

We are not talking anything amazingly complicated here. I am doing some work with optics and...

Best software for block diagrams?]]>

Suppose we have the following equation, knowing that ##B## is a constant, $$\frac{dU( \theta)}{d \theta} + 2Br = 0$$ where we want to solve for ##B##. If we differentiate the above equation with...

Solving for constants in a differential equation]]>

What is the physics of motion through space?]]>

What software or tool is used in this video to present the material this way?

Thanks]]>

The sodium D-lines are a pair of narrow, closely spaced, approximately equal intensity spectral lines with a mean wavelength of approximately 589 nm. A Michelson interferometer is set up to study the D-lines from a sodium lamp....

Fringe Visibility of Sodium Doublet in Michelson interferometer]]>

dx

Where,

dx

∂

I...

Tangent and Cotangent Bases]]>

]]>

validity of ray optics in telescopes]]>

How to recharge a 12V battery using an Alternator]]>

So I'm studying Gover's Algorithm and I have this doubt:

Does 'Phase inversion gate' grows exponentially? I mean, if I want to signal the one combination that is the answer, I must be able to represent all 2^N states, where N is the number of qubits in the system. How do I do this without...

Does 'Phase Inversion' grow exponentially?]]>

Possibly post#4 may be of some relevance too.

I have already described my view more or less at length before (post#83 and...

Recursive Ordinals and Creativity]]>

If you have an hamiltonian, that has time has a variable explicitly, and you get the lagrangian,L, from it, and then you get an equivalent L', since L has the total time derivate of a function, both lagrangians will lead to the same equations euler-lagrange...

Hamiltonian and Lagrangian in classical mechanics]]>

Looking for some help on how to go about finding the natural frequency of a block of foam. The foam has a density of 0.37 lbs./ft^3 and is 48"x48"x8" (LxWxD) in size. Weight is approximately 5.4 lbs.

I have been digging around the internet for quite some time with no such luck...

Natural Frequency of a Foam Block?]]>

A grid made of ropes is suspended by its four corners with strings tied to four different points on a building. Three of which are fixed and fourth is attached to a pulley which is in turn fixed to the building.

Given data :...

Tension in 4 strings suspending object at 4 different points]]>

Circular Motion — Object on a rotating conic surface...]]>

and I'm somehow fascinated by the idea to get rid of dark energy as only explanation of...

Expansion without dark energy]]>

A body that is on a horizontal surface begins to move under the action of horizontal force equal to 60% of its weight. Force acts for a while, then stops acting. Determine the total time of movement if the body has traveled a...

Movement of a Body on horizontal surface]]>

If you have the following equations:

=>S+U=90

=>S+U=90

and

=>40S+25U=2625

=>40S+25U=2625

you can then rewrite S=90−U and then substitute.

Now you have a single...

Why do equations with two distinct variables with 2 distinct]]>

Main question (if it applies to you):

Does that saying apply to you? And if so why would we treat a friend better than ourselves?

Secondary, although...

You wouldn't treat your friend as you would yourself?]]>

Anyway, I found out that cost so much, for example there...

Why an MBA is so expensive?]]>

L = (d/dx +ia) where a is some constant. Applying this on x, gives a result in the subspace

\begin{equation}

L: \mathcal{H} \rightarrow \mathcal{H}

\end{equation}...

Operator mapping in Hilbert space]]>

Salt was used in food preservation, with its abilities (Which abilities? I have never understood this...) and...

Salt or Sugar?]]>

View attachment 216801

As frequency is decreased to threshold, no. of emitted electrons will remain same, but their maximum kinetic energy will decrease....

The effect on a photocurrent of reducing the frequency of photons]]>

That thees super heavy particles exist....

Is supersymmetry dead?]]>

A beam of rectangular cross section 200 mm deep and 100 mm wide. If the beam is 3m long, simply supported at either end. And carries point loads R1 to far left, R2 to far right, 1m to left 5kN load, 2m to left 10kN load.

(a)...

Simply supported loaded beam]]>

]]>

I have a semi-conducting sample which has been run on a PPMS system - measuring it's resistivity as a function of temperature.

I switched to AC transport mode in order to measure the resistivity again while applying frequencies between 1Hz -...

AC transport data query (using a PPMS system)]]>

Second moment of area of a hollow triangle]]>

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

Weird News Compilation]]>

View attachment 216788

The probability of getting a state with energy ## E_v## is ## \frac { N_v } { N_v +N_c } = \frac1{ e^{-(E_v – E_f)/k_BT} +1} ##...

Conduction band, valence band and Fermi energy]]>

Drop the Physics Requirement to Encourage More Women Engineers?]]>

Where C = capacitance, ε0 is epsilons constant, K = dielectric constant, A = area of aluminum foil, and D is the...

Calculating how to make a homemade capacitor]]>

Spacetime as geometry]]>

In Einstein’s thought experiment, let one of twins travel to a galaxy known to be 10 light years from Earth at a speed of sixty percent of light speed (0.6c). Were it not for time dilation the one-way trip would...

Does the "space twin" benefit from length contraction?]]>

Do most textbooks not help their readers?]]>

2017 Member Awards Coming Soon!]]>

Typographical question: the section sign]]>

I was playing around with various sets of numbers while thinking about optimizing neural networks and was wondering if numbers derived as below have a specific name

given a set: [7, 5, 3, 8, 1, 5]

the difference set is [-2, -2, 5, -7, 4]

the difference set for that is [0, 7, -12,...

Do numbers derived from successive differences have a name?]]>

Delete automatic updates .. problem?]]>

A Mag 5.6 earthquake in Pawnee, Oklahoma happened this morning.

http://earthquaketrack.com/us-ok-broken-arrow/recent

2016-09-03 12:02:44 UTC

36.429°N 96.923°W

6.6 km depth

That's somewhat...

Mag 5.8 (upgraded from 5.6) Earthquake, Pawnee, Oklahoma]]>

"Space and Stuff"]]>

What is the physical interpretation of imposing the following constrain on a Hamiltonian:

[tex] Tr(\hat H^2)=2\omega ^2 [/tex]

where [itex]\omega[/itex] is a given constant. I am not very familiar with why is the trace of the hamiltonian there.

Thanks in advance,

Alex]]>

Reverse Alphabets

We had a contest on the Alphabets recently, and this contest will be similar to that one except that we will go backwards,...

PF Photo Contest - Reverse Alphabets (12/9-12/22)]]>

I have a circuit which I have a current through labelled I on circuit. I have -9.18 +j17.31. we agreed this was correct. I have a node analysis problem but cannot find the correct answer. I feel my method and my maths may be off but...

Node analysis]]>

Does anyone have any book suggestions for a beginner like myself that present the theories in accurate ways without going into all the mathematical formalism? Preferably something that is not tied to one interpretation of the...

Books for overview of QM and/or QFT?]]>

I encountered this weird theory that I don't really believe to be valid. But it sounds pretty plausible, so I'm going to let you guys tell me whether it is correct or not.

Anyway, the link is here: http://www.onelife.com/evolve/degen.html (warning: possible...

Human Genome Degeneration]]>