Classical Physics

Let me just start by saying that i have had no formal education in engineering or physics so excuse me if i have trouble expressing my thoughts, but recently i have been extremely confused on the theory behind voltage potential. So in this book I'am currently reading it states that voltage is the measure of energy of electricity as energy per unit charge. Now they are saying that specific unit of charge is measured in coulombs, now this is where i get confused, is voltage the amount of energy that is gained after one coulomb is forced from one fixed point to another? or is voltage potential just an invisible force like a magnetic field that is just static and when one cou…

Kinetic Energy seems easy to understand. For instance, if you throw a football, or any object, away from you. Your act of throwing, requires movement on your part. This movement is transferred to the object, which then itself starts moving. As it moves, the distance between you and the object continually increases. This continually changing distance, reveals that the object has acquired extra (kinetic) energy. That's clear. But I can't understand Potential Energy. Suppose you don't throw the object, but just lift it up, and put it (say), onto the roof of your house. Up there, it's supposed to have acquired extra (potential) energy. But once placed the…

I've heard it said that there are four dimensions. Length, width, depth, and time. These are all things that we measure. They have dimensional properties. What about wieght? and temprature (or enropy as some say)?

at 6:17, the equation should be [math]\Delta v = v_f - v_i[/math] but the vid shown that it substitute [math] v_y [/math] into the equation [math]\Delta v = v_f - v_y[/math] which would result in [math]\Delta v = v_f - \frac{1}{2}v_i[/math] does I miss something here? or Khan just do another mistake?

ei heard something like that

according to the theory of relativity nothing can move faster than light. so then why has a craft that moves a substantial fraction of the speed of light been so elusive (such as .05) or even .25)?

Curious, if matter expands when heated and contracts when cooled, why do pipes burst when they freeze? I mean shouldn't it get smaller, not burst?

so i was playing with some water baloons and i wasnted to make a morter for them. so i thought about it and i had this idea to find the hight and force of the water baloon (the force of when it comes down) if you guys could give me a formula that would be great please tell me if i am missing any thing in this post

Okay, so i just watched the mythbuster episode with the killer deck myth. i know it can't actually kill people but i thought "hey that would be a cool thing to do" and since i only have two urgent things for uni i done some solid practice at it. i must be doing something right because my plasterboard wall is covered in tiny cuts everywhere and my mum looks like she's going to rip my throat out via my nostrils. through experimentation i know its all about spin and most of that comes from the wrist but how fast do these things have to be spinning to cut half a centimeter into plasterboard(drywall in the US i believe)?

hey all, by no means am i a physics major, or professional, but i know a little bit...with that in mind, i was posed a question by a fellow fireworks enthusiast over the weekend. so here goes. basically we're trying to calculate the recoil force of an aerial shell upon launch. there's a second part of the question that might be a little too complex given the information we have, but i'll get to that in a bit. ok, so lets say the shell weighs 100g, and attains a height of 200ft. given that information, what is needed to calculate the force of the shell in motion, as well as the mortar tube it's shot from (given that every action has an equal and opposite reaction)…

Hi Guys , This is my First Post here on this forum.... As we all know that , in a ceiling fan , Electrical Energy is transformed into mechanical energy ... I want to know where does the Mechanical Energy goes after wards ? It has to go somewhere ... Because Energy can neither be Created or Destroyed !!

In "wonders of the universe" I was slightly confused by the description of entropy. Prof Cox used the example of a low energy sand castle and a high entropy pile of sand in a cone. Can the grains of sand in the sand castle really only be arranged in that order to create a sand castle? Surely there are many ways the grains could be ordered to create a sand castle; and is this number really massively less than the cone of sand which he claimed was high entropy? I also wondered if Prof Cox's hairstyle was low or high entropy? At first sight it looks like a high entropy system but I would imagine over the course of the day it flattens out....so presumably it is actually intia…

Hey guys. I would like to ask according to the conservation of energy, energy can't be created or destroyed. Then, where is energy come from??

Is it possible for us to create a space which absolutely empty with not even single particle do exist in it? Or perhaps is it already exist? please tell me if u know..

I was just wondering if position could be a derivative of something itself, for example existence over time?. If not then can it be broken down any further in any way? What does position mean? Thanks for your time.

I intend to improvise the existing Air cooler. I am attaching a tube which compresses and de-compresses the air so that it cools.the cool air then goes into the air cooler to give out more cool air. Is my theory right ? I also want to attach a dynamo to the motor shaft so that it produces energy while using it. Thanks in advance

in a pipe , open and closed at the ends, the frecuency is [math]f=(2n-1)\frac{v}{4L}[/math], if [math]L[/math] decreases, then [math]f[/math] increasses. I don't understand why in a text of physics of music (in spanish) says: "in a pipe, closed in the vocal fold, and open in lips....in the lips there is antinodes of velocity... if the lips widen, then frecuency increasses" someone tell me the mathematics asociated to this afirmation?

If light has no mass, why is it affected by gravity?

an Jet plane of mass 3x104kg. and total wings area 120m2 is in level flight at some height .The difference in pressure between the upper & lower surfaces of its wings in kilo pascal is ?? a)2.5 b)5 c)10 d)12.5

During my strange peregrinations on the web, sourced by a thread on this forum I hit on the Wikipedia article about Archimedes Eureka. At the end of article 2, we can read the following My question is: is that correct? In the source link [4] (from Galileo’s treatise) , we can read the full concept and in-between the following: Which looks more correct to me. Your opinion?

As a learner of Physics I am very much interested to know about the EM waves and EM field. As far as I know, the Electric filed and Magnetic filed are perpendicular to each other and that makes the EM field propagation. EM waves are fluctuations in that field. Radio waves, micro waves, IR,visible light,UV, X-ray, and Gamma rays are EM waves at various frequncy ranges. I want to know why do the frquency ranges vary? Which makes them to vary and how? are the electric and magentic fields are spread all over the universe? are they fade away when getting farther away from matter?

So if I take a ball and just drop it, when it hits the ground, the ball transfers more kinetic energy to the ground than if I just set the ball on the ground. So, how does gravity cause this increase in kinetic energy being transfered to things and how does it not run out? The energy and momentum has to be coming from somewhere...

I've heard from some of some things that Masaru does that microwaves change some of the properties of water and makes the ice crystals form all weird and ugly. But, I can't find any valid experiments anywhere and I don't know exactly what microwaves are doing to water as to cause it to have different properties. Can anyone help me on this?

I'm not saying cooling reactors would stop the decay, but could you cool them down with liquid nitrogen and super-cool them by removing the medium that carries the heat? I don't know if you can actually really cool a nucleus reactor because the nuclei of atoms breaking down are constantly causing fission reactions which then release energy.

In a universe full of all sorts of Particles and Waves, does the change of state of the particle or wave constitute merely a change or a passage of time . ( if so who's time ) . If only change exists does it matter going from state A to state B or from state B to state A . Does this constitute time going in the opposite direction.