Classical Physics

From what I understand, electric currents create magnetism because electricity is a current of electrons and electrons are negatively charged causing magnetism. But then why wouldn't an object be magnetic at all times, even when there was no electric current flowing through it, since all objects have electrons (nevermind ionization)? What is it about electrons moving (giving rise to an electric current) that makes the object more magnetic?

I am supposed to perform an experiment in class where I have to measure the mass of some little plastic bottles. I believe there are different coloured bottles and there are a certain number of items inside each coloured bottle (so each bottle with the same colour should have about the same mass). I am not sure how but this experiment is supposed to represent Millikan's experiment in which he tried to determine the elementary charge. Could someone plz help me out and lemme know how to go about finding the number of items in one specific coloured bottle. I m kinda lost so ur help would be much appreciated and also if some1 could describe how this relates to Millikan's …

Hi everybody! As you may define "Force" as a "push or a pull", then how would you go about defining momentum in the same way. Please don't use "mass*velocity" stuff, I've read it thousands of times in my textbook and it doesn't really explain the actual meaning of momentum. Thx.

If we have a star, let us give an example of Alpha Centuri and a object orbiting it let us label OBJECT X. assume Object x is 1/2 light years away from alpha centuri. if ( and this will not happen, so this question has little purpose) alpha centuri is wiped out of existance, when will OBJECT X stop being influenced by its gravity? suddenly? or after half a year? can no message travel faster than light? and does this link in with the Graviton the assumed particle of gravity

Sorry this was too funny to pass up: Evangelical Scientists Refute Gravity With New 'Intelligent Falling' Theory August 17, 2005 | Issue 41•33 KANSAS CITY, KS—As the debate over the teaching of evolution in public schools continues, a new controversy over the science curriculum arose Monday in this embattled Midwestern state. Scientists from the Evangelical Center For Faith-Based Reasoning are now asserting that the long-held "theory of gravity" is flawed, and they have responded to it with a new theory of Intelligent Falling. Rev. Gabriel Burdett (left) explains Intelligent Falling. "Things fall not because they are acted upon by some gravitational fo…

Why does root mean square velocity has importance in Kinetic theory? Whats its specific importance? I mean why not just mean of magnitudes or cube-root mean cube velocity etc.??? I don't know more abut statistics, so please help... hrushikesh

I understand the idea behind a siphon, however I have never found any mathematical explaination that states how long it will take for water to flow. I've seen fluid dynamics text which talk about fluids flowing from vessels but never specifically about siphons. If anyone has any direction then I would appreciate it.

Angular momentum is conserved within a system. My question is: can the universe be seen as a system in which angular momentum is conserved? aguy2

1. What effect does atmospheric pressure have on evaporation rates? (I know a higher pressure raises the evaporation rate, but I would like some formulas if possible) 2. What effect does atmospheric pressure have on sublimation points? (Specifically, in crystals? Again, a formula/equation would be very helpful) Thanks for your help guys!

I have some questions, 1. What would happen if newton's first law were violated? 2. What would happen if newton's second law were violated? 3. What would happen if newton's third were violated? Also, what would happen if forces were not equal in magnitude and acted in the same direction? I know that in Newton's third law were violated, the conservation of momentum would not be valid. Please don't answer by talking about the conservation of momentum.

...really descriptive title, I know. I was wondering about the physics of devices in which air bubbles pass through a liquid and then out again. I got to thinking about a straw, and how the water is moved through the tube. You have two openings, one in the cup which is really big, and then the end of the straw which is really small. If you reduce the pressure on the straw end the water gets pushed up the tube by pressure on the other end. But what if you reduce pressure on the cup side? It seems that the air will bubble through the liquid and out. Is this because there isn't enough pressure to push all the water out? My question is how you can tell whether…

Here's a very basic pressure question: Suppose I fill a balloon with very pure water, and place it in a vacuum chamber. What will happen? (Assume there's absolutely no gas present in the balloon.) I can think of several scenarios: - nothing happens, because liquids don't expand - some of the water will vaporize, because it's being subjected to vacuum, and will expand the balloon - very little water will vaporize, because the elasticity of the balloon creates pressure, so nothing happens Can you help me out? Airmid.

Actually, I was more interested in the effects the turbulence has on the 'pulse' itself. Could the turbulence's influence on the pulse be akin to 'canister shot' or some other appropriate analogy? aguy2

I really dont know where to go with this one. A boat sails across a straight river of uniform width W, starting from a point O on one bank of the river. The velocity of the river at a distance y from the bank is u(y)=ay(W-y), where a is a positive constant. The boat travels at a constant speed v relative to the current and steers a course set at a constant angle p between 0 and pi. in the downstream direction. a) show that the velocity of the boat is (u+vcosP)e1+(vsinP)e2. b)at what time does the boat reach the other bank? c) show that when the boat has reached the other bank, the downstream distance it has travelled is equatl to [tex]\frac{aW^3}{…

Imagine you're immerging a shpere, with a diameter d, in a liquid. What will be V(x), where: x is th height of the immerged part of the sphere V(x) the volume of the part that is immerged for x=d, V(x)=4/3πd^3 and for x=d/2, V(x)=4/6πd^3

Instead of impulse, for example? They are both conserved. When putting energy into an object, its \delta velocity is not directly proportional to the KE added (but is directly prop. to impulse). For this reason we say that a car needs more gas to accelerate by a constant amount the faster its moving (see other thread). But it doesn't take more impulse. If we based energy on impulse, we wouldn't say it takes more gas. Right? Can someone explain? thanks!

anybody know of a good way to observe a microwave at ~2.5 ghz? I ask because I have to make a cavity that resonates at this frequency, but I have know way of knowing when I'm right on the money. and furthermore when I'm using the cavity I need to see any fluctuations that occur in the wave. I have access to an oscilloscope if that helps any. I'd be very thankful for any help

Hi, I have been studying Statica for the past month. And I can say with proud I am finally starting to get it. I am stuck however on a problem I made up myself. Something is probably wrong in my way of thinking. Excercice: Let's say there is a framework of 2 equal horizontal iron pieces both are attached to opposing walls at the same height. In the center they are joined together. Next there's a cable hanging in the connection point. The cable is connected to a weight of 20 Newton. The angle of the cable (alpha) as seen in the picture = 89,99° (or almost PI/2) My answer: I solved it in 3 steps... 1) first of all the sum of the external vertical powers …

Say you're driving in a car pretty fast. You hold out an object in your hand and push it out in front of you, the same direction that the car is moving. You would feel no more resistance than if you were travelling at 0 m/s right? But aren't you doing more work on the object? You're forcing it over a greater distance because the system is moving faster? But it wouldn't feel any different... Consider you and the car to be the external system. Could someone explain? This is related to what someone told me: that in a car, it takes more gas to increase your speed by a constant increment when you're moving faster because the engine needs to do more work on …

My first question is basically does a vacuum work in space. For example: You are traveling through space and pass through a cloud of dust, could you take a sample of the dust cloud with a vacuum or would nothing happen? My second question involves sound in space. Now i know you can not hear sound in a vacuum but does a vacuum effect sound waves. For example: if a focused wave of sound designed to shatter stone on earth, would it work in space? Would there need to be changes to the wavelength for it to work in a vacuum? Any help to settle my curiosity would be appreciated .

How can I change torque, like the motion generated by an electric motor, to a linear force, like the force generated by a linear motor? What kind of device would do this? The motion should be piston-like. Okay, let me elaborate more: I'm building a Beta Stirling Engine that will act like a cooler. I will run it using another Stirling Engine, and the torque will be applied on the flywheel of the cooler. The drive mechanism is too complex. I was wondering if there is simply a way to convert a wheel's motion into a linear force WITHOUT any angular or side motions. I should attach a drive mechanism to the wheel, and I want the end of the drive mechanism to have no side moti…

I`ve heard of "Black Body Radiation", and that silver is the best reflector and matte black would be the best absorber of IR radiation, but what would be the optimum color for transmiting IR heat? I currently have a seriously modified parafin (kerosene) heater, the inside flame burns Blue now inside a flue that`s silver on the outside and matte black on the inside, the flue is about a foot high with a fine holed, thick steel mesh ontop (I can cook perfectly well on this!). but the flue is still smooth silver on the outside, and since it`s job is primarily heating and through convection, is there anyway I can boost its Radiant heat by changing the color of the outside …

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While we are told that g = 9.81 m/s/s, this is only an approximation and isn't necessarily always true when we do precise calculations. Since, by the Universal Gravitation Laws, acceleration is determined by the mass of each object and the distance between the objects, we can't necessarily use a "fixed" gravitational acceleration of 9.81, since as we are free-falling gravity's acceleration changes as a function of distance. In fact, even mass changes as we accelerate. I've always wondered how we could compute the true free-fall for an object of mass m as it falls. Any ideas?

Howdy, this idea may be flawed, may have alot of bugs, but it's something I think is fun to tinker with. What if gravity is simply the absence of virtual particles? Like, matter exist, it creates some form of field which pushes or inhibits virtual particle formation, then it creates something sort of like a space vaccum. Like with the Casmir effect. The reason light can only travel so fast is because it has the capacity to only push X amount of virtual particles out of it's way at a time, and so that limit inhibits it's capacity to travel through space, which would mean in curved space time you'd travel faster. The reason that things would slow down while…