Physics

Is voltage the potential energy difference between source A and B in a circuit? If so in absense of resistance and the presence of a 3V battery does point A have 3V to begin with and at point B there is 0 volts. Is all potential energy converted to kinetic energy when moving from A to B? A is origin and B is the terminal end of the circuit by the way. Is that voltage drop? If what I have said is not correct and voltage doesn't drop like this does a circuit with no resistor and negligble resistance from the wires have 3V at point A and also 3V at point B? Let's say that I have a circuit like this (made it linear for ease) 3V battery--point A----------------1oh…

I watched this video and wondered if physics or science, would be able to explain these events.. http://www.youtube.com/watch?v=YLJRX0w3m_I

Hello everyone, This forum has finally helped me to answer nearly all my questions, which even my teachers could not help me with. One question remains unanswered to me though. I was recently told of the experiment to prove the quantum mechanics theory of atoms being everywhere at the same time, literally. Since I don't know the name I'll try to describe it. You have a material with two gaps near the middle, at the exact same distance from the middle as each other. Particles, whether photons or something else it does not matter are fired at one of the holes and as it comes out the other side an interference is causes (I'm unsure of whether this technical …

What is proof of E=hf ?

How strong is the Lorentz force on nanoscale? Would the Lorentz force of an electrical circuit of only nanometers thick (such as carbon nanotubes) be powerful enough that arbitrarily nearby objects would be significantly magnetically influenced?

Thus, you make the crime because you pushes me on crime, - I can not widespread the theory of magnetic holes to physicists. Most of them do not know how dangerous they are. You do not let me to widespread the discovered crude errors which were made in the CERN’s safety documents. Physicists, where are your mathematically grounded answers? Are you able to disprove my assertions about crude errors of CERN? No? Consequently, these documents are falsifications, made in order to prevent public resistance. LHC in a dozen of days can explode the Earth. What can I do? To take hostages, in order to attract the attention of ordinary people. Because you, physicist…

My question is in regards to a starling resistor. A starling resistor is where a flexible tube passes through a box that can have it's pressure changed. If fluid passes through the tube then flow through the box will be determined by the pressure differences from the two sides of the box provided the pressure on both sides of the tube outside the box are greater than the pressure in the box. If pressure in the box becomes greater than the downstream pressure of the tube coming out of the box then flow will be determined by the difference between the upstream pressure and the pressure in the box. The tube will collapse at a point where the pressure in the tube becomes…

Ok this makes sense but pressure inside an airway is determined by hydrostatic pressure and when air moves fast hydrostaic pressure is decreased and converted to kinetic energy. So this collapses the airway. My question is doesn't kinetic energy of moving molecules exert a pressure on the walls of the airways. Why is it that only hyrdostatic pressure determines the pressure inside an airway? Thanks!!

Hello everyone, Normally if there is 1 kg object and I apply 10 N force it would accelerate at 10m/s. Here the acceleration is determined by the mass of object. How does gravity in the absense of resistance make objects travel at a fixed acceleration? In a centrifuge a force equivalent to double or triple gravity is used. Does this force give a constant acceleration (9.8m/s2) like gravity too. How is that done? Thanks!!

since X rays have more energy than UV rays, does that mean that they will cause the same chemical reactions as UV but faster?

Hello everyone, I find this so contradictory so please help to understand this. In vasoconstriction, 1. The flow of blood should increase but this would also mean higher resistance so does the flow increase or not. Normally when we constrict something we expect higher speed don't we. 2. In vasoconstriction pressure should be higher but again does the resistance decrease the pressure. My questions for vasodilations are exactly the same but vise versa. Thanks for anyone who is going to help

In starling forces only hydrostatic pressure is taken into account. I don't understand if blood is moving through a capillary don't they have to take velocity pressure of blood as well? Thanks!!

How do these machines work? I mean there is no such thing called centrifugal force in real yeah. It is basically inertia. So can anyone tell me how it can be used to separate molecules and how different masses move differently. I haven't see the machine yet so if you can explain that would be great. Thanks!!

Hello, In science there are so many equilibrium concepts. Pressure, electricity ,concentration..... Everything seems to be moving from high to low to reach equilibrium My questions are 1. Why does everything try to reach equilibrium? (Extremes are generally harmful and for survival of this word equilibrium is required is that the reason) 2. From where do the particles get energy to move from high to low and how do they know they have to move from high to low to reach equilibrium. Thank you very much!!

Hello everyone, I have made number of topics recently I think they have all stem from my poor understanding in this matter. Ok in a gas, molecules can take up a volume and exert a pressure. Inside a fixed container when you increase the temperature pressure increases because more gas molecules are hitting the walls. Now in a liquid the molecules are close together and volume is determined by the shape of the container. So inside the container liquid molecules don't hit the walls and exert pressure some other way. What is this way. Is this called hydrostatic pressure. Also when you make the molecules move faster in a liquid somehow would that increase the pres…

What is it? I don't understand. If there is a bucket of water and you put a tube inside the bucket and blow at one end and then release water flows out of the tube. Why does this happen. Also when you raise this tube water stops. Why? This is not homework or anything.

does UV radiation have the ability to break up water molecules? if so please specify the wavelength

if you have a shorter wavelength of UV, will more ozone be produced than if you have a longer wavelength?

Hello, "Potential Energy (PE) + kinetic energy (KE) = Total Energy When air travels through an airway at a CONSTANT FLOW RATE, the total energy of the fluid (PE + KE) decreases because friction converts some of this energy into heat. Since the fluid is moving at a constant flow rate, the loss is in potential energy (decrease in hydrostatic pressure)." I don't understand this. Shouldn't the moving object lose K.E. Shouldn't resistance decrease speed. I think the reason for that is I don't understand what is hydrostatic pressure, I researched but I don't get it. "As we move down the airway, the tubes begin to narrow. When a tube narrows, fluid velocit…

What are air bubbles? In the typical coke can analogy. As you open the can carbon dioxide goes out as bubbles. Are bubbles created when there is a sudden change in pressure. Emphasis on sudden there. Thanks for the help

Imagine an ideal gas that is cooling down by radiation (it's probably in space somewhere, and it's warmer than it's surroundings). The individual gas molecules have to emit a photon in order to cool down (probably, but not necessarily, in the infrared). What happens at the moment that a photon is emitted? It must mean that the molecule is colder now. Temperature and velocity of a gas molecule are related (velocity is a function of the square root of the velocity). So, does the molecule instantly slow down? And can this photon be emitted just in mid-flight of the molecule (without interaction with a second molecule), or only when it collides or interacts with…

Sorry, I was unsure which subcategory this should go under. I was having a sci-fi discussion recently and talking about means of intersellar propulsion available to possible advanced cultures. Would it be possible to somehow tap vacuum energy to create a force to propel a spacecraft? What would you need to harness it? Could you, for instance, have positive energy created infront of the spacecraft, pulling it forward, and negative energy created behind, making the spacecraft/space expand away from it?

the simple explanation for the reason light travels slower through water than a vacuum seems to be that when light is traveling through water the photons are absorbed by atoms for a short time and then emitted to be absorbed and emitted by other atoms. in a chain reaction kind of progress, the light eventually is transmitted through the water. is this just an oversimplification or is there something that causes the photon to keep moving in the same direction it was moving before being absorbed. why isn't the photon emitted in a random direction ?

Hello everyone, The partial pressure of the atmosphere 33 feat benath the surface is doubled the normal amount. (2x760 mmHg). I can understand how lower you go down higher the pressure but I don't understand how you can measure atmospheric pressure under the sea. I mean under the sea you got water around you not atmosphere. Are the gases in atmosphere dissolved in this water. My question is mainly related to divers under the sea. They get double the atmospheric pressure of nitrogen and nitrogen narcosis could occur. So how do you get double the N2 in the atmosphere when you are surrounded by the sea. Also why do these effects occur when divers are using an oxygen tank…

There are two masses connected by a light rod with length l, a vertical axis is at a distance x from one mass. Suddenly the axis is removed, and the system spontaneously has the axis shifted to the centre. L=mwx^2 + mw(l-x)^2 L'=2mw'(l/2)^2 = (mw'l^2)/2 L=L' (conservation of angular momentum) w'=w[(2x/l - 1)^2 +1] so w' must be greater than w. L = L', E = Lw/2 so the system energy increases, and I think this is illogical, how come a system can have its energy increases spontaneously (without any driving force)?