Can an Electrostatic Fluid Accelerator inflate a balloon?]]>

- Dry Air Gas Constant of
**286.9**from The Engineering Toolbox - Dry Air Gas Constant of
**287.22**from...

Why does the Dry Air Gas Constant vary?]]>

How to remove Ethanol from Gasoline?]]>

I don't know what "I" is nor do I know what "A" is but it has to do with sound waves.

May you also please correct me if I am wrong but is:

ρ = density of air

v = velocity of sound = 343 m/s

ω = angular frequency of the sound wave = 2πƒ

And also may you...

Can someone explain to me these equations of sound waves?]]>

1. Papers

Recent Noteworthy Physics Papers]]>

I've been reading up on EM waves and I feel I'm slowly starting to get it, but I'm not entirely sure if I do, so I was wondering if anyone could help so I can be sure I'm not making some false conclusions here. I can't seem to find any answers to the less certain parts here

So as I...

Questions about light waves]]>

A 'gravity battery' could be created by using an energy source to slowly lift a large weight (using gearing or pulleys), then discharged by lowering the weight to...

Another 'Gravity Battery' Question]]>

How did they derive this formula?...

Rod falling faster than gravity]]>

I have a small confusion regarding the formula that calculates the luminous flux of a light source, which is given by:

View attachment 114990

(See this Wiki)

The ##\bar y (λ)## is the so-called luminosity function...

Lumens and the Luminosity Function]]>

I have a question for you guys and gals. I am working on a Desalination project and am ironing out questions about efficiency. What would be the most efficient temperature to evaporate water? 50, 100, 110 degrees? Does it make a difference, or is the energy required to evaporate a fixed...

Most efficient temperature to evaporate water?]]>

If you put a sealed device on a scale and place in an air tight box then fill with air pressure would the weight change of the device if there was a leak? I am trying to do a test to...

measure air leakage]]>

View attachment 114970

The way I originally learned it was just to look at it and do this :

MX1''=-KX1 -...

2 methods same answer dynamics]]>

I can't quite understand this very simple thing.

Prof Shankar's introduction to relativity on Youtube starting at about 50 minutes has a quick calculation that comes up with the Lorentz transform.

I follow the maths, no...

What Does Shankar Mean? Intro to Relativity]]>

These days I am studying rotation and rolling of bodies. We know a body can be made to rotate about any point. Let's assume that an external force is acting on the rotating body fixed about the point of rotation, and this force made the body rotates faster that is its torque produces...

Torque Equation about a point other than point of rotation]]>

X-Ray scattering in crystal]]>

Linear Momentum, in classical mechanics, is the product of the mass (the measure of an objects resistance to acceleration...

[Question] Did I figure out the Space Shuttle's momentum?]]>

Beam-powered propulsion - keeping the beam focused]]>

I was wondering what the relationship between the photon and the electromagnetic wave is? Is the photon traveling on that wave like a surfer is riding a wave? :-)

Thanks in advance!]]>

What about a situation when we have a sphere whose radius is R, and it's half full with...

Water pressure in a sphere]]>

How do you calculate the terminal velocity of a fluid through a pipe.

My problem includes turbulent flow, very high reynold number, and water (incompresible).]]>

If you know any, please advise.

Thanks,

Robert]]>

This is my calculation..Am I on the right...

Force to stop a person on a treadmill]]>

but!

after that, the sound waves form a cone... what is that? is that the head of each wave being produced behind the previous wave and then blasting...

What do the sound waves look like after Mach 1?]]>

Preferably in an if.... then..... because...... statement.]]>

For now, it seems that the forces exerted on the block are balanced - thus it doesn't accelerate.

The forces exerted on the floor are, however, not balanced. The floor is not accelerating downwards, I must then...

A block on the floor - forces]]>

Gauss' gun/magnetic linear accelerator]]>

New energy creation]]>

Problems from Lev Landau's "Theoretical Minimum"]]>

Magnetic Levitation]]>

General relativity vs quantum mechanics]]>

But i dont know what causes the phenomena

View attachment 114858]]>

Conceptual Understanding for Voltage in a Circuit]]>

Time to equalization]]>

many thanks

Ewen]]>

Cheers...

Antenna inside of a cavity]]>

I need help in coming up with a function that would accurately predict what the temperature inside the box would be after say.. 5 or 10 minutes.

Basically, I need to come up with a...

Coming up with a function to model expected room temperature]]>

Superluminal speeds -- Princeton study year 2000]]>

The lens needs to be 120mm long, with its focus at a max distance of 80mm

the light traveling out of the lens needs to be parallel...

Designing a planocovex PMMA lens]]>

2)What is electricity in relation with a electron? I know it is the proportional to electric charge, but what relation does it hold? Is...

What is Electricity? Insights please...]]>

Magnetic fields and moving electrons]]>

As you can see in Picture 3 two wires parallel to each other will attract each other if the current is going in...

Magnetic field around a wire]]>

Understanding laser power terminology]]>

"Fine Tuning" constants]]>

What I don't understand is why this sharp...

Sharp ended lightning rods]]>

- By brushing a metal surface to create a matt finish, the surface of the metal becomes rougher....

How does the surface property affect blackbody radiation?]]>

There is no way to convert angular momentum into forward momentum.]]>

My question is that I don't understand the optics/physics behind the reason why Si-based CCDs are not sensitive for IR-light (above 1000-1100 nm) if on the top of the p-type Si there is a SiO2 layer which...

Refraction of IR "light" in CCD sensors SiO2 layer]]>

Related to - Thermionic emission]]>

eV = ½mv2

Where e is the charge of...

Thermal motion of an ionised gas molecule in an electric field]]>

I have an optical system conisting of a laser source, a lens with some focal length F and aperture stop `(with some diamater D), followed by another lens (with another focal length) f and aperture stop d at some distance r from the first aperture stop D. What...

External focus in an optical system]]>

The question basically asks you to compare the thermodynamic cycle of water in a typical thermal...

References on thermal power stations and supercritical technology]]>

I do reloading of ammunition for competitive shooting (Cowboy Action Shooting).

I have someone offering to sell lead for melting and casting bullets. He has indicated its source was shielding from hospitals used in X-ray shielding...

Is lead salvaged from hospital x-ray shielding safe?]]>

Observation of laser pulse propagation in optical fibers]]>

Calculate approximate speed of a collision?]]>

Why there isn't a scattered photon in the Pe effect?]]>

I'm a second year undergrad and we've covered the heat equation,

\begin{equation}

∇^{2}\Psi = \frac{1}{c^{2}}\frac{\partial^2 \Psi}{\partial t^2}

\end{equation}

and the wave equation,

\begin{equation}

D∇^{2}u= \frac{\partial u}{\partial t}

\end{equation}

in our differential equations...

Similarities / diffs between diffusion & wave propagation]]>

Where to place fixed axis of rotating motor]]>

My understanding for why a basketball bounces is that the earth acts against the ball, causing it to deform due to the ball having a downwards inertia and wanting to continue travelling down. This deformation reduces the volume inside the ball, in turn increasing the air pressure which...

Why does a basketball bounce?]]>

The entropy

Why is entropy a state variable even for irreversible path?]]>

My Confusion: As the current passes...

Extended Faraday disk]]>

1) cause: ?

2) effect: motion]]>

Water pressure and flow restricton - does size matter?]]>

My example scenario is kinda odd but goes like this. You are a paratrooper. You have just jumped...

Survive falling into water. Calm vs Disturbed]]>

Magnet clamp repelling in coil]]>

Could I combine the two resistors together in parallel to make an equivalent resistor, and then use that equivalent resistor in series with the capacitor?

It would be great if there was some rule of thumb that I can use to know what I can make into an...

Not sure what I can make into equivalent resistors]]>

Voltage across two different circuits]]>

How the wave impedance of free space works?]]>

In order to understand it better, I need to know the physics behind a falling...

How does an angled rod behave upon collision?]]>

My question is what are the necessary setups?

I know that I would need a strong magnet like neodymium magnet. But, i have no idea about the formula. Lets say i...

Magnetic Levitation Formula]]>

Chief Ray Angle and Field of View]]>

Entropy on a Small Scale]]>

Solar vacuum tubes]]>

I know running for one hour it uses 60 W x 3600 s = 216 kJ of energy.

Does that mean it uses 216 kWh of energy?

Or does kWh means 60 W x 1 hour = 60 kWh?

I am confused because the units in 60 kWh is not in their simplified terms.

More specifically, this pertains to...

KWh versus kW times Time]]>

I suppose this comes down to a broad question about the physical nature of fields in general. I love the Einstein-de Haas effect, where an iron core spins in the opposite direction of the induced spin angular...

Does a rotating magnetic field possess angular momentum?]]>

https://en.wikipedia.org/wiki/Eternalism_(philosophy_of_time)

OR

https://en.wikipedia.org/wiki/Philosophical_presentism

OR...

Do most physicists believe time flows?]]>

I'm trying to understand the perspective distortion that can be observed in our vision and cameras, so many pages on the web that talks about photography says that the perspective distortion can be controlled using different focal lengths lenses, meanwhile a reduced group of pages...

Is perspective distortion mathematically modeled?]]>

Sir, actually in a tank by the toricelli's law and also from bernoulli equation, we have outlet velocity as V= (2*g*H)^(1/2). In the case 2, I have closed the pipe exit partially with hand and observed a higher velocity than case 1, in practical. but...

Tank outlet velocity exit pipe cross-section area dependence]]>

Ideally we want to be able to...

Electromagnet Levitation, stationary hoverboard - How?]]>

Confusion about the magnetic field]]>

Does a probability distribution correctly describe entropy?]]>

Lower microwave absorption efficiency to increase penetration (cooking)]]>