Physics

I was thinking about roads being the energy supplier to a new-type of vehicle. If the streets can be made to absorb solar energy and transmit that energy to a new-type of vehicle, then a city can be energy efficient. A rode model to show a country how to be energy smart and clean. Any thoughts?

It's said that Rotation is when an [rigid] object turns about an internal axis e.g. a merry-go-round or gramophone record whereas Revolution is when an object turns about an external axis e.g. the Earth around the Sun. So why are gramophone record speeds given in terms of Revolutions Per Minute (RPM) and not Rotations Per Minute because the whole of the record is rotating about an internal axis?

could you have something like a fan, wich the propellers were connected to small generators, and theres also mini windmills on the blow-side wich take in energy from there too. would it make more than it used? it uses 2 energy supplies to make it, the mechanical energy of the fan blades moving, and the wind energy from the moving air. i think it might help if it was all in an airtight "shell" too. and if it could work then it could also be used in bigger curcamstances.

If light were to blink on and off and the speed of light continuously, would the light appear to be on or off?

alright the Casimir is proven that light travels faster in an absence of matter faster than the universal constant of V so assume you have you have a three km long chamber encasing an electromagnetic field and you could accelerate an object to the speed of light then you removed the electromagnetic field and it broke the glass at this point it is traveling at more than the speed of light which is against the laws of physics because it wasn't always traveling faster than light would it dilate at an equal rate to its declaration or will it simply continue to move faster than light ?

This seems like an invention that might have interesting applications in chemical reactor engineering. (The effect is purely physics though, which is why I posted here). A thin liquid film is subjected to two perpendicular electric fields. This causes the film to rotate. I will just link to the sources for more explanation, because I don't quite understand it myself. - Original article (.pdf), titled "A liquid film motor" - Decent summary which links to the original article. I think it could be great to be able to stir a reactor without having any moving parts (other than the liquid itself). What other applications can you think of? This post is more a "…

My calculus lecturer mentioned in passing something about how shining a torch onto a screen via a small hole would create a series of rings of light (on the screen) that could be modeled as sinc2 of the distance from the center (the lecture was kind of just about the sinc function, really). Annoyingly, he didn't mention what the effect was called so I couldn't read up on it. Does anyone know what effect I'm talking about? What it's called? Why it happens? (I know nothing about optics, but this sounds kind of interesting)

I know the human body is mostly third class levers, making it operate at a mechanical disadvantage. What would happen if the human body were made of first or second class levers?

hey, i want to be an aeronauticall engineer, and im just wondering if any one would be nice enough to type down any formulas i should know to help me out. i know theyll teach me it then, but i dont want to wait, im curios and i want to play with these formulas once i learn them. get a head start too. when i say formulas i should know, i mean things like newtons f=ma and equations showing how to, say, determine how much fuel would be needed to accelerate to x amount of speed. please, and thanks. should i have posted this on the engineering thing or the astronomy?

Why does the hydrogen (3,2,1) wavefunction look so similar to the field lines generated on this CRT?

Can a mathematical statement/equation describe the following? If a thing displays at least two verified characteristics which are impossible to reconcile mathematically, then it does indeed have each of those characteristics -- simultaneously. The reason I ask concerns the first time I heard about light's wave-particle duality in my studies. I had immediately resisted the idea of a contradiction, that light just had to be either a wave or a particle. For there was no dilemma, because a photon could travel as a particle...yet in a wave-like motion. See the images for an example of this. (It's difficult to imagine I'd be the first person to offer this solutio…

I understand that Work is not a vector quantity but a scalar. The definition of Work = Force x displacement. So if I apply a force of magnitude X to an object causing a displacement in a certain direction doesn't that constitute a vector?

If area doesn't enter into the equation for the amount of friction, why do racing cars have such wide tyres? Thanks.

Hi, we are in Physics 202 and working on a few problems that we cant solve. We had a BUNCH of people working together and cant seem to get any of these. Q1- Consider a parallel plate capacitor with area A, and seperation D. A large insulation sheet is inserted between the plates. It has dialectric constant K. 1) What force acts on the sheet if the voltage is kept constant? 2) What force acts on the sheet if the charge is kept constant? 3) How does the sheet affect the energy of the capacitor for 1)? 4) How does the sheet affect the energy of the capacitor of 2)? Q2- 2 metal plates of area A form a capacitor. The bottom plate does now move but the top plate…

I wasnt really sure were to put this Theory but, here it goes and i'd also like to see others theory of time as well and are what you though about mine, I do blive that Time is doing notthing but folding back in on it's self over and over, such as a 4d cube would if you were to make one, And with that being said, Past, Furtere, and Percent, would become one so there for Not only what you've done done in the past 5 mines and are what your doing now for that matter happen but, It has happen will happen and is happening now if you can rap your mind around that anyways More on this topic if you guys even understand what I mean i know im not the best speller in the world so …

So this is a complimentary thread to Building a HV AC Capacitor. The capacitor being built in this thread was plexiglass with aluminum foil plates immersed in mineral oil in what I would assume to be a baby jar. So I thought hmm what a great way to try to do some physical chemistry maths. Here is the perfect opportunity to model heat transfer and dissipation for a practical purpose. I have all the equations and would like to give it a try. I have however none of the info on glass(I would have to assume a commonly used type,) mineral oil and plexiglass; aluminum is easy to find. So before I actually try to do this for the practical purpose of letting the composer of …

A principle takes a while to become a law. However, when the time comes, who makes the decision for this to happen and be officially recognized as such?

How can I make AND, OR, XOR, and NOT logic gates in an electric current. The power source could be a battery and I can connect parts using a copper wire. But how can I make these logic gates? Whats the simplest way?

What form is the best for the lowest friction if a rod needs to spin horizontally on a flat surface? something like this |----------- ------ = the rod | = the flat surface is there some kind of design that can be etched in them to make the rod turn as easy as possible?

Hi, I am working with a couple of highschool students on a physics project their class is doing. They have to construct a yoyo that will fall a distance of 2 meters in the GREATEST amount of time. Mechanical friction cannot be used as a means of slowing the yoyo down. The maximum allowed mass is 1000grams and the maximum diameter / length is 20cm. We came up with a square shape and a thin rod in between. We acheived a time of about 3 minutes. Now today one of the students talked to me about the 'competition'. Apparently a rivaling group claimed to have gotten the yoyo slowed down to 45 minutes over the 2 meter drop. I have thought about how this is pos…

Im studying electric potential in my physics class, and I need some clarification on the concept behind it. The electric field of a point charge is capable of extending an infinite distance, right? Does this mean that electric potential spreads to infinity as well? Im sorry, I should know this by now lol Any info is greatly appreciated...

there is a promising new development involving invisibility using an exotic new material called "metamaterial", which may one day render an object truly invisible. ironically, the creation of metamaterials was once thought to be impossible because they violated the laws of optics. but in 2006 researchers at duke university in durham, north carolina, and imperial college in london successfully defied conventional wisdom and used metamaterials to make an object invisible to microwave radiation. although there are still many hurdles to overcome, for the first time in history we now have a blueprint to render ordinary objects invisible. (the pentagons defense advanced researc…

Hello, In the diagram below, you have a U shaped container full of water. You have two red objects being dropped into the water at the two tips of the U shaped container. Both objects are equal in all respects (same density, same material, etc.) except for their size (and therefore their mass as well). What happens when they are dropped into the water: do the water levels stay the same as each other or does the larger object push the water level down on its side more than the other side gets pushed down (so they're unequal)? NOTE: This is not a homework assignment - it is school related (a physics course) but I'm just having trouble understanding the concept. …

Do the electric impulses in the body travel at the speed of light? For example, if something brushes your toe, or your eye detects a flying mosquito, does it sent the info to our brain at the speed of light? I'm not asking how fast the brain processes the info, just how quickly it's reached by the signals.

In previous threads, i have mentioned that i am building a tesla coil with no physics/electronics knowledge beyond what I have taught myself. So if you see something in the paper about a kid blowing himself up it's probably me. lol. But anyway, I need to build an HV capacitor somewhere between 1 and 40 nF rated for close to 28k volts to account for surges and gains in the capacitor. so i did some research... eventually i chose plexiglass for my dielectric. I picked up some .093 inch plexiglass at Home Depot, and proceded to cut out 3 inch squares. i then made 2.5 inch circles of aluminum foil using the bottom of a can and alternated between aluminum and plexiglass, lini…