# All Questions

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### Can this type of graph be analysed to produce any meaningful data?

The above is a graph of pendulum length on the x-axis measured in metres, and pendulum period on the y axis measured in seconds. The pendulum period is not squared. I know that if I square the ...
75 views

### Far Field Diffraction of EM waves: what does the zero frequency signify?

If you have a system of independently radiating electrons/point-charges, the far field distribution of the EM waves can be approximated by the fraunhoffer diffraction integral, or simply by the ...
4k views

### Can there be black light? I mean is it possible to devise a machine that outputs darkness?

I understand there are various colours that light can have. But i was wondering why there is no 'black' light. What is the logical explanation for this? I mean I am expecting an answer that goes ...
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### Questions about the formula used to determine inductive reactance and $Z_t$

I am currently on the inductors unit in my Navy schooling and I have two questions about these formulas that I learned about. As I'm aware, the ability of an inductor to concentrate a magnetic field ...
47 views

### How do the flow equations relate to the actual situation?

This question might seem silly but I'll try to make it clear. It's a question (I think) about partial differential equations systems in general, but since currently I'm studying fluid mechanics I'll ...
55 views

### How can one reasonably theoretically model polycrystalline materials?

Many techniques are taught in advanced solid state courses but they are almost all derived for perfectly crystalline materials. For example, band structure really only appears theoretically when you ...
92 views

### Force field for Calcium ions, potassium ions and water in molecular dynamics

I want to adapt my existing MD simulation so that it can handle these three species. For the interactions of the ions I thought that I would use the coulomb potential, but I don't know what sort of ...
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### What type of the charge particle were there at time of formation of the solar system according Nebular hypothesis.? [on hold]

When our solar system created by nebular hypothesis or any other theory. What type of the particle would be there? Charged particle? Are these accelerating or moving with high speed with different ...
152 views

### Is any energy required to deflect an asteroid, with force always perpendicular to its trajectory?

Let's assume there is an asteroid traveling on a straight line (far from any gravitational source), and we need to deflect it from its actual trajectory, so we build a rocket motor on the surface and ...
19 views

### What is the speed at which hydraulics take place

Consider a long pipe filled with some newtonian liquid, with piston at both the ends. You push the piston at end A, and observe it at the other end B. How much time does it take for piston at B to ...
15 views

### light movement, not in a straight line [on hold]

In physics class our teacher asked when the light doesn't move in a straight line, why, and how can we use it.I looked for an answer all over the internet and found photography sites and the physics ...
3k views

### Why does the current stay the same in a circuit?

I was informed that in a circuit, the current will stay the same, and this is why the lightbulbs will light up (because in order for the current to stay the same, the drift speed of the electrons need ...
92 views

### Point group symmetries and unit cell

I was wondering if the unit cell (of a given lattice) had to have every point group symmetries of the lattice it defines ? I guess there is no unique way to define a unit cell and that it may not have ...
8 views

### Conventional flux in centrifuge?

The molecules sediment in centrifuge, which is rotating with angular velocity $\omega$. The chemical potential of molecule (considering potential associated with centrifuge force) is: ...
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### Number of States and Required Info for Bits vs Qubits

So with classical bits, if you have 2 bits, there are 4 possible outcomes that are possible. To determine these states, you only need 2 pieces of info, the state of each bit. With 3 bits, you can have ...
54 views

### Ampere's circuital law for finite current carrying wire

When I was studying about Ampere's circuital law. Then there comes a question in my mind that "whether this law is applicable for finite current carrying wire or not"
879 views

### 6 wheels more efficient than 4 wheels?

Which would be easier to push in a straight line, a flat cart with 4 wheels or the same cart (and same load) with the same size wheels, but has six wheels? and why? Thanks
29 views

### “Voyager: Lightning on Jupiter”: what's a sound source for this?

NASA created an official Soundcloud channel with a various sounds from missions. There are a Voyager: Lightning on Jupiter sound. Is there are ay information on how's this sound is produced (and ...
21 views

### Friction Force and Applied Force for Acceleration [on hold]

A person needs to move a 565 N object. The coefficient of static friction for the surface it's sitting on is 0.63. How much force is required to accelerate the object at an initial rate of 0.4 m/s2? ...
126 views

### Dielectric constant of water

I need the dielectric constant of water from $10^{-2}$ Hz to $10^4$ Hz. As stupid as it may seem, I cannot find much info. I've googled for days. All I can find is close to GHz. And the only info ...
17 views

### Interferometry works as a filter

I attended an astronomy seminar the other day and though I did not pick up much as it was on data collection etc, I did take away one sentence: "Interferometry works as a filter" Now I know what ...