Classical Physics

WWII era subs used diesels on the surface and attained faster speeds than when switched to electric motors while submerged. However, modern atomic powered subs attain higher speeds while travelling submerged than on the surface. This seems counterintuitive in that more of the hull is in contact with the water and therefore more friction with the water than when on the surface. So my question is, how/by what mechanism do submerged submarines travel at higher speeds than while on the surface?

Can anyone please tell me: in what direction does a point on the surface of a sphere accelerate when: the sphere is spun on an axis which is in-turn spun on an axis orthogonal to the first and that 2nd axis is spun on an axis orthoganal to the previous two: This relates to a brief discussion that I had with someone about the moulding of Easter eggs(!) Would the chocolate just slosh about or does it all get uniformly pressed to the inner surface of the sphere?

Do the laws of Mass and Energy conservation not apply at the time of Big Bang?

I was studying a link that Studiot pointed me toward when I suddenly realized that refracted light is turning. It didn’t sink in right away that reflected light was also turning, but then it did. Is there a difference , should there be a difference between them and acceleration? I have a tendency to draw conclusions because I see things that seem similar, I’m beginning to think that maybe I’m wrong in doing so. Also, is there a difference between a photon following curved space time, and refraction? overall, I know that they are different things, but the results are similar.

passing a continuous current through itself. When the device is placed within a magnetic field, the magnetic flux lines exert a force on the semiconductor material which deflects the charge carriers, electrons and holes, to either side of the semiconductor slab. I wonder why the semiconductor needs to send a current through itself in order for the protons and electrons (positive and negative charges) to get effected by the magnet and get to either side of the semiconductor. There are only negative charge in the current of course (cause it's all electrons, which should result in the electrons getting to one of the sides of the semiconductor, but how does it wo…

Hi, I know that voltage is the potential energy, but I wonder how it's measured. For example, how do they measure the hall voltage in magnetic sensors (image attached), or how do smartphones measure the voltage in the battery to show the battery life? 

Hello everyone, my name is Harald Tamer Linke and I'm 16 years old. At the moment I'm trying to get a little deeper into astrophysics and for doing such I'm trying to learn some formulas f.e.: the equation for universal gravitation: F = G*(m1*m2/r^2) But my problem is that when I try using this equation for an example, instead of Newton I get Newton/m^2 as result. Here is my equation: The gravitation between two objects (70kg and 80kg) with a distance of 3 meters: F = G * (m1 * m2/r^2) = (9.81N/kg) * 150kg * (80kg * 70kg/(3m)^2) = (9.81N/kg) * 150kg * (5600kg/9m^2) = (9.81N/kg) * 150kg * 622,22..kg/m^2 = (9.81N/kg) * 93333,3...kg/m^2 …

I wonder why the speed-cup in this case will follow the magnet: Since they're electric currents, and they're moving in an electrical conductor inside a magnetic field, another law of electromagnetism says they will create motion. How? The currents actually make the speed-cup rotate in such a way that it tries to catch up with the spinning magnet. Source: https://www.explainthatstuff.com/how-speedometer-works.html

I have a big assignment for school, in which I will be researching wether or not it is dangerous or not to wear cheap sunglasses, as you have your eyes more open when there is less visible light, if UV was to come through cheap glasses it could be dangerous. Now I do understand why some wavelengths of UV have a higher penetration power, however I don't understand what defines what material is good at letting UV through or blocking it. Is it just density? Does is have something to do with the way molecules are arranged? How could I find what is a good UV blocker, and why it is?

Hi, I wonder how turbos in cars can compress the air it gets. I've heard that the air compresses because the compressor wheel spins very fast. Why is the air compressed because of that?

I’m searching for solid materials that don’t left residue when burning, or left a very small amount of it. Any suggestions on such materials?

I think classical physics is the most interesting field of science.

The experiments that proved there to be no luminiferous aether did NOT prove that there is no "universal up" or "universal down." Universally, up is always away from a gravitational well and down is always toward it. This isn't the same thing as there being an "absolute up" or an "absolute down." Or is it the same thing? Can anyone explain why these two things would be different? Use your math and explain. I can explain how they are the same. Using my math.

Watch the launch of Blue Origin. It should raise a few queries for the enquiring mind.

how to calculate it ? question 9

I would like to collect reasons to discard the idea of ether. If there are reasons not to dismiss that idea, I would also like to collect that.

Hello, everyone. I have been trying to understand the meaning of the question from the posted image. I think that preloading has to do with adding bolts to the cantilever beam such that it can withstand the force from above, but I am not sure how exactly these bolts should be implemented. I would also like to generate a meaningful equation based on the information provided.

When I think the word mass I invision a blob that can be large or small, which is not very discriptive, and probably has little to do with mass. Is the more specific meaning, mass = (The resistance to change, in motion.) ?

Hi,everyone I am a HongKonger I study physics in english . Now, I am learning force and motion but I forgot the concept of the normal reaction and weight , my teacher said I have to read the book to learn it again but I think the most important is `how to calculate the force ` I think those concept is useless . I want to ask is it useless for know the concept or good for know it? Also , I want to ask how to study physics effectively . （my English is suck ,there may be many grammar mistake,please forgive me)

Posit a flywheel as a gyroscope, rotating clockwise Now consider the flywheel pierced at regular intervals aeound the circumference, and in each piercing there is another gyroscope rotating widdershins. and that the sum of their angular momentums is equal but opposite to that of the larger flywheel. [latex]\sum_{1}^{4} L(small~gyro~n) = - L (large~gyro)[/latex] What behaviours or peculiarities could be expected from such a framework, even before force was applied to the [latex]Z[/latex] axis?

Consider identical guitars, with one in a heavy case and the other in a light case. Both cases are indestructible, the guitars are snug-fitted in a similar padded interior for this scenario. If I drop both cases from some height, which guitar will fair better in terms of experiencing the least shock? Another question: Would a loose fit or a tight fit be better in this scenario, given the cases are otherwise the same?

Have this sort of setup right now. Pane of glass with led light passing through it. Droplets of different liquids to test emission. Is it possible to get the light to come out more vertically from any droplets instead though?

My Physics text in High School contained the following statement, as closely as I can recall it: "X-rays may be bent and diffracted by means similar to visible light". I asked our instructor, if x-rays pass freely through a glass prism, how can the text's statement be valid? He was a recent college grad., his academic background unknown. He kind of shrugged, and as he usually answered the "unanswerable" said, "Read the book!"

so would variables themselves be dimensions such as if I am defining a car then can I define that as being a "car" dimension? And then can I use that car dimension as being part of a graph?

Problem: A particle of a mass [math]m[/math] is embedded in a circular rail, (radius: [math]R[/math]), without any friction. In a given moment, the particle finds itselfs without velocity at point C, and a force is applied on the rail, which starts moving with an [math] \vec A[/math] constant acceleration. Use a non-inertial system fixed to the rail to solve the problem. Arrange the Newton's equations, and find the movement equation of the particle. (It was originally in spanish that's why I only screenshoted the graph) My attempt at a solution: \( \vec F_v = bending force \) So I manage to integrate \(\ddot \varphi \) so i get \( \dot \varphi (\varphi)…