# Questions tagged [applied-physics]

The tag has no usage guidance.

217 questions
Filter by
Sorted by
Tagged with
1 vote
104 views

### Deriving the Cable Equation from Maxwell's Equations

My goal is to reach equation 12 on this wikipedia page: Cable Theory. The demonstration is usually done by making an infinitesimal circuit, but I would like to get there via Maxwell's Equations by ...
63 views

### Okay, I know the risks. ( Amateur Rocket.) [closed]

I am currently attending a school for electrical science. A small group of students and our instructor are attempting group project to build a liquid fuel rocket. (I know it is a bit out of the scope ...
88 views

### Applications of Schrodinger's to dark solitons [closed]

The Schrodinger equation (SE) admits dark solitons as particular solutions. The SE and the The Korteweg-de Vries (KdV) equations can be used to model them. Questions: What are the applications of ...
• 99
2k views

### Calculating temperature when it is lower than your thermometers can read?

We have an old freezer. I believe the thermostat is broken and think it may run all the time. Food in it gets really cold (Ice cream like concrete). I've tried measuring the temp with a freezer ...
• 163
48 views

### How would I calculate the heat change of compressed air?

My friend is working on a snow gun, which involves using compressed air to blow apart water coming out of a pressure washer. I read that you can cool air by compressing it, which makes it hot, then ...
286 views

### Why does radar have a much longer range than infrared sensors? (in the context of military aircraft)

In the context of military aircraft and missiles, radars often have ranges of hundreds of kilometers, while thermal infrared sensors can only barely reach 100 km in the best of circumstances. But ...
• 540
1 vote
64 views

### Application of Schwinger-Keldysh formalism in various topics except cosmology

I want to find some theories or models on Schwinger-Keldysh formalism (in-in formalism) focusing on flat spacetime in terms of correlation functions. For example, I know there are many applications ...
358 views

### Where special and general relativity must be used in engineering?

As I know Newton physics is used for most engineering, aerospace, mechanical, naval etc. Where we must use Theory of Special Relativity and Theory of General Relativity to get correct results, only ...
• 613
62 views

### Why do some microwave meal instructions violate the 'Specific Absorption Rate' rule?

Do Microwave oven heating times grow linearly with Wattage? Calculating optimal heating time states that the product of the microwave power and cooking time should be constant. However, some meals ...
• 1,879
57 views

### Predict color of dye under a certain wavelength of light?

I am picking fluorescent dyes to be put under a UV of known wavelength and would like to be able to predict approximately what color the dyes will appear under the light. I can request ...
• 21
1k views

### What technological advance would a room temperature superconductor allow? [closed]

I have read a recently published paper on arXiv where the scientists claim to have developed a superconductor material working at room temperature and pressure. While it is clear that the results - if ...
1 vote
9 views

### What is the state of the art in nanophotonic biosensing?

Over a decade ago I've been doing research in nanophotonic biosensing and all the reviews from those times were very impressive. Some plasmonic structures were capable of single-molecule detection and ...
• 3,034
84 views

### Physics in the kitchen: does heat transfer faster from air into oil or from air to food when in an oven?

It is usually said that foods cook faster in an oven when coated in oil. While I can understand that the underside of the food will cook faster where the oil forms an thermal interface between the ...
• 425
103 views

### Applications of infinite square well/particle in a box

I know of only two instances where the infinite square well is an adequate model for experimental behaviour: the absorption wavelengths of cyanine dyes, and extremely small semiconductors to which ...
• 101
1 vote
37 views

### Functionalizing iron oxide nanoparticles for antimicrobial activity [closed]

I'm working on my thesis which is about synthesis of iron oxide nanoparticles from a plant leaf extract and testing the particles activity on bacteria to measure their toxicity towards it. The thing ...
1 vote
100 views

### Thermoelectric effect

Hey just learned about this thermoelectric effect in physics class, I was wondering why it is not used more often in the form of a thermoelectric generator in practical industrial applications. Would ...
• 27
107 views

### How does CT imaging deal with the thickness of materials?

In the medical CT imaging field, image of an inspected object is obtained through xray projection. xray is attenuated by the inspected object through the formula $I=I_0e^{-\mu t}$. The projection $p$ ...
1 vote
37 views

### Pendulum similarity with a ball attached to a uniform disk with constant [closed]

A particle of mass $m$ is supported by a frictionless horizontal disk which rotates about a vertical axis through its center with a constant angular velocity $\omega$ . The particle is connected by a ...
78 views

### Millimeter Graph Curve Type Question

I have question regarding graphing on a millimeter graph, with which I'm sure most of you are familiar and I apologize for it's simplicity. For example, if I graph the period squared over the length ...
50 views

### How is it possible to receive 2 pulses from only 1 sent pulse?

If we have a sample of a certain material to characterize it The sample is a cube with side length (L=1m). You used an ultrasonic (US) transducer to send an US pulse of frequency (f=5MHz) at normal ...
737 views

• 171
222 views

### Internal energy and conservation of momentum

The book says that if the net of all external forces acting on a system equals zero, the system's(centre of mass of the system basically) momentum is conserved. But what if some internally stored ...
88 views

### Applications of nanomechanics

What are applications of nanomechanics beyond its use in atomic force microscopy? The question is specifically about the existing applications rather than the potential/future ones (which are quite a ...
• 60.3k