Classical Physics

Hi Everyone, I have an idea about what is magnetic force. Please comment/feedback. Thanks! Two poles of any magnet, one surface plate is electron concentrated and the other surface plate is electron less. So one pole is positive charged and the other negative charged. Because all those electrons are bonded by protons in the magnet, we see attracting and repelling forces between two poles but we can not see current. Stronger magnet has higher unmovable electric charges on two poles.

According to the ancient Greek philospher Zeno, you can never reach a pre-specified destination because you must travel half-way, then half of that, and half of that, down to infinitely small values. http://en.wikipedia.org/wiki/Zeno%27s_paradoxes#The_dichotomy_paradox As Aristotle said: Here is the equation that "proves" it: Essentially there are two standpoints, one philosophic; that you can easily reach your destination, seeing as it happens all the time, or the scientific, which I already explained.

I'm one of the people in my city researching renewable energy ideas, and it seems as if the length of power lines is less of a factor in planning electrical systems is less of a factor than in years past including sites about a global power grid. Corporations, of course, do have ulterior motives to claim success for technologies that don't work or are speculative on their sites, cost, level of development etc.?

Hi. i just started physics this year so im not too deep into it yet. just had a question about center of mass. we were doing a centripetal force lab, spinning small weights on a string over our heads and varying the mass. so my question is: As your spinning the weights overhead, is the center of mass simply the midpoint between one end of the weights and the other end on the string (all the weights are the same). Or would the center of mass be at the end of the string. this is probly a stupid question but im just making sure.

1.To avoid a potential collision with wildlife crossing the road, the driver of a car travelling 105 Km/h fully applies the brakes to stop as quickly as possible. If the car stops 3.8 s after the brakes are applied, what is the braking distance? 2.A vehicle comes to a stop 10.0 s after the brakes are applied. While the brakes were applied, the vehicle travelled a distance of 75.0m. If the vehicles acceleration remained constant during the braking, what was the vehicles initial speed? 3.Based on a reaction time of 1.50 s and a braking rate of -5.85 m/s, the stopping distance of a vehicle travelling 90 Km/h would be? 4.A high performance car initially travelling…

I was revising vector calculus recently, and couldn't help but incorrectly have a train of thought about its interrelation with the calculus of variations, and the relevance of both in Mechanics. After thinking about this for a bit of time, and resolving some of my previous confusion I have ended up with a simple question. I have learned that a quarter of a cycloid is the curve that satisfies and is a solution to the Brachistochrone problem for when we assume gravity to be constant. However, I was wondering, what kind of curve is a solution to the same problem when we don't assume g to be constant, and take the familiar newtonian expression for it? Also does this bear…

Hi, everyone. I am very confused over these three terms, electromotive force, potential difference and voltage. Just exactly what is the difference between them? Can anyone explain these in simple terms for me? I need to explain it to a bunch of 14 year old but I can't. Also, if you would not mind, please include a more advanced explanation to me. haha. Thank you. I hope the community can reply as fast as possible. ^^

If you enjoyed Crayola physics, you should know there is an older game quite like it. It's name is Armadillo Run, and it's really awesome... If you enjoy physics you will certainly like it, I did

Hi Everyone, I am working on a project which involves a motion sensor which contains a 3-axis accelerometer. My goal is to determine the position of the sensor in 3D space relative to some starting point. At first I thought that just the accelerometer was all that I needed but after thinking about it some more it appears that this solution is not adequate. Of course determining position from acceleration is simple a double integral estimation which is not terribly complicated. My concern is that the position is relative to the accelerometer itself. I am imagining a scenario where you move the sensor in the +Z direction (for simplicity assume it…

Hi, Could someone help me out on this problem : If p(momentum)/m(mass) is .92 c(speed of light), what is v(velocity) in terms of c? I'm not sure how to do it. If p=mv, and p/m is .92c, than shouldn't v be .92c as well? But that's not the answer =? Any help would be appreciated! Thanks

OK, I know this is simple and I'm just having an issue tonight. A simple pendulum, is damped, Theta is the angle from vertical hanging. There should be a change to either the KE or PE of the system due to the damping... But I can't remember what it is, I *think* the PE should change to: [math]U=-mglCos\theta + A\dot\theta[/math] Where A is some constant of friction... The reason I ask in this way is because I'm trying to do this using Lagrangian mechanics...

I'm trying to figure this out: If you were to (hypothetically, under ideal conditions) reform a fossil fuel, say gasoline, into hydrogen, and use that in a fuel cell and through a motor to produce mechanical work--- would you be able to produce more work than by using the fuel in a heat engine that operates at its maximum theoretical efficiency (i.e. the carnot engine) ??? Remember, the electric motor, fuel cell, reformer and such can be calculated at their highest theoretical efficiencies.

Newton's 3rd law of motion states that for every force, there is a force equal in magnitude and opposite in direction. For example, when a five pound book lays on a desk, it exerts five pounds downward on the desk. At the same time, the desk pushes upward on the book five pounds. But what about when the net force is not zero? For example, a free-falling object in a vacuum. Where is the equal and opposite force there?

Could gravity just be an effect from the expanding universe? Since the universe occupied such a small space at the start then it would seem that the space between each particle has increased. If this is true then wouldn't the space between particles still be increasing? So in effect every particle is accelerating away from every other particle and in doing so distorts space/time and causes the effect we call gravity. The more massive the object is the more accelerating particles it has and so the greater the distortion on space/time.

There is a thin ring of mass M radius R. At each direction, north, south, east, and west, you have a rocket that pushes with a constant F newtons. Each rocket push vector is Nx,Ny, Ex,Ey, Sx,Sy, and Wx,Wy. The ring's center of mass is moving at V so that Vx and Vy are the components of velocity in the x and y direction respectively. The ring is also spinning with an angular velocity of Z radians per second clockwise. The rockets are much lighter than the ring so that they don't really affect any calculation due to their relatively small mass. What are the linear and angular accelerations of the ring?

Hey guys, I'm trying to figure out how the pulley system / gearing works on something like this - http://www.chapman-leonard.com/products/telescoping%20crane%20arms/15'%20Telescoping%20Hydrascope.htm Basically some kind of pulley system make the front 2 telescoping sleeve move in and out in unison as well as making the back counter weight slide to compensate for added or subtracted force on the front end. In addition the places that the camera is mounted stays level to the base as the crane is arced up or down. Any ideas? another picture - http://www.panavision.com/product_detail.php?imgid=158&id=110&cat=103&PHPSESSID=6kn8scjcplmgfn5i5nlnop…

If you have a rod, or more simply 2 very small masses connected by a massless rod of length L (each mass being equal; M kgs.) You then connect a massless rocket thruster an x distance to the right of the center of the rod so that the thrust is always F newtons perpendicular to the rod. How would the system behave? O, and before people start saying how massless things don't work, then say that the mass of the rod is .0000000001 * M and the material behind ejected out of an equally light rocket is lighter a million times lighter than that, but is going at a very very large velocity close to the speed of light so that its dP/dt = F This is how I tried to solve it: …

Lets suppose I have a fan attached to a motor in complete vacuum. The electrical energy supplied to the motor is converted into the kinetic energy of the fan. Now I replace the motor with another one which rotates in the opposite direction. I keep the switch on till the blades slow down and stop and switch it off before it begins to rotate in the opposite direction. Lets now compare the initial and the final states. The kinetic energy of the fan is the same before and after the event. But I have spent some electrical energy. Has the enegy been lost? If it is lost, then the law of conservation of energy does not hold. I know I am wrong but I don't know where. Because Phy…

Hello, Given a copper tube with capped ends, of 150mm in length, 28mm i/d and a wall thickness of 1.5 mm, can anybody give me the formulae for calculating the pressure that it will withstand prior to rupture at an amb. temp. of +20 deg.C. at ground level? Any answers would be appreciated. Kind Regards, nitro

Hello. I have certain ideas for a computer games Serious Sam 3, and I would like to ask about certain fission here. So, the sniper rifle, in my vision, has a single drop of water instead of gunpowder. And thanks to some sort of fission, it acts just as the above powder, because energy of its molecules is released thanks to fission. And also the speed of the above bullet is twice as fast, when compared to the bullet with usual gunpowder, talking about the same rifle. So that is my question, that is, will I make a fool of myself if I suggest this idea on SS3 forum? Thanks if you know.

Hi I have a simple question: How does the QM and other mainstream physic theories describe the structure (topology...) of a photon ? Thanks

Hello, I AM going insane now because of my physics class. We're learning about Newton's Three Laws (First, Second, and Third), and frankly, I understand what they mean. But when it comes to actual mathematics, I really do not know how to do them because my teacher does not teach me well. I ask questions and all I get is some gibberish! Can anyone offer me advices on what I should do? I've read the book and took careful notes on the words AND practice problems but still, the progress is not very good. I have high A on that class but the truth is, I don't really "understand" it... I don't know... I already have a full year college calculus credit and took two years…

I understand how the doppler effect works and I'm trying to work out the speed of an object traveling at 50 k/ph (assuming I don't know it's speed of course) If I were to use a radar and send a lightwave at the object at about 10.6 GHz and found the returning signal to be 1075 Hz higher than the original, how would I work out the speed? The speed and frequencies were chosen at random, any numbers will do, I'm just trying to understand the formula used. Also, does the speed of the earth effect the result? Any help would be greatly appreciated. Thanks

This seems like the type of question which probably either has a stupidly trivial answer that will make me blush or a stupidly complex answer that will make me sexually aroused... Why does air consist of 79.1% nitrogen, 28.9% oxygen , 0.1% argon and a few other things (or something like that) at sea level rather than there being a distinct level of mainly carbon dioxide with a layer of oxygen on top then a layer of nitrogen on that and a layer of argon on top with other lesser things between? Is it just simply down to wind? If I fill a jar with air then leave it, could I later open it and remove different gases in a variation of fractional distillation?

Take a look at this video and the way that the equation is derived. It seems to be OK, although it's a bit different from the standard one: http://youtube.com/watch?v=tjv5NYItg1w Is it?