Classical Physics

HI All I have been doing some reading, as far as I understand - science may be in for a shock!! If a machine were running at 96% efficiency and were able to produce 4 times its power output over its input power, would that not break Newtons Law? please email me on your further interest email deleted

+ A science observation : A dry surface " say Plaster" can appear quite light when dry. ( say light pink or white.) On the addition of wetness , for example water, the hard surface of plaster will turn instantly quite dark. + Question. What does water do at the surface that turns the phenomenon from reflection to absorption ? +

I was wondering if anyone could tell me what things are are liquids at temperatures below -70 kelvin. I know the boiling point of liquid nitrogen is -77. Are there any others?

Hi all. Imagine two extremely large 'two-dimensional' objects -say like a brutally large flat sheet of paper- where their thicknesses is irrelevant in relation to thousands of square miles. Would their centers of mass still be a point ? - If no, what shape would it be ? - If yes, would bringing those two bodies together make their intergravitational attraction nearly infinite, impossible to pull them apart ?

If two light streams of different strength (in terms of photons per second, same wavelength) meet diagonally, will the smaller light stream be absorbed into the larger light stream? Will their directions change?

Hi Folks, Are there any physical phenomena or systems that can be well described once they have reached a steady state but for which it is seemingly impossible to describe how the components of the system system get into the steady state ? I'm thinking specifically about systems in harmonic oscillation, where all of the component forces & energies are balanced as they interact with each other, but where there appears to be no logical way in which each of the components could exist or be described individually prior to their (balanced) participation in the whole. Cheers Rich

Revered members, Kindly see my attachment. i) vcosθ in a direction parallel to OY. (ii) vsinθ in the direction perpendicular to OY. The component vsinθ has no effect along vertical diameter YOY' since it is perpendicular to OY. Revered members, why the perpendicularity of vsinθ to OY makes no effect along vertical diameter?

Four forces are appplied to one point with different angles. What is the net force assuming that all horse drag with the same force? Sketc the corresponding angle. i need some ideas on that plzzz

Achieving higher temperature has always been easier to obtain then achieving low temperature "One can simply use a easy to get torch lighter to easily go over 1000°C) However without using consumables such as dry ice, it has been much more difficult for someone to achieve lower temperatures. The only common items available to the consumers within the price range are usually a normal compression cycle refrigerator or the highly inefficient Thermoelectric Cooler (TEC) Wanting to obtain temperatures low enough for a cloud chamber experiment and other low temperature experiments without using consumables such as dry ice or liquid nitrogen, has anyone had success …

How fast can i spin 2inch by 12inch round 1018 cold roll steal. I am looking for 10,000rpm?

I'm splitting this off from the Stirling Turbine thread. I made a modification to the vortex tube and it is finally showing some action. I knew that the capillary tubing from the old air-conditioner that I was using for the "injector" or whatever it's called had a slightly smaller orifice than than recommended, by something like 1/2 mm. I thought if I added another, the two combined would be slightly over specs. (too much air input ?) but I figured that it was worth a try anyway: I looped another piece of capillary tubing around to the top and opposite side as shown, drilled the holes and soldered it into place. I plugged it into the compressor h…

Generally, most of the research I have done says that neodymium magnets do not loose their energy, even when dropped or around other magnets, and will last 400 years. But what about if the neodymium magnets are constantly in motion and interacting with each other? Our system has a Sphere neodymium magnet moving along a "magnet track" with Cylinder neodymium magnets, similar to this Youtube video: We need to know HOW MANY PASSES a sphere magnet can make before the cylinder magnets along the magnet track loose 10% of their energy. Our system has a sphere magnet passing at a speed of about 1.0 m/s, 3 times per second, so lots of magnetic activity. That mea…

Revered members, Kindly see my attachment. The linear velocity acts tangentially along AH and BT. The particle moves from A to B. Velocity BT is resolved horizontally and vertically along BC and BD Change in velocity along horizontal direction = vcos(theta) - v Change in velocity along vertical direction = vsin(theta) - 0 Can i know why it is v in first case and 0 in second case?

Gravitational force between two bodies is equal to G*m1*m2/d^2. Does this formula work for finding the force of gravity without interaction with another body? Such that the gravity of a single isolated body is equal to G*mass/d^2? Or does it have to require an interaction? Also for F = M*a, this formula gives the instantaneous force at a particular location right? Is this the same for the force from G*m1*m2/d^2? Is gravity the only type of force that is affected by the inverse square law? I don't learn the math yet, because I am still in a basic physics course. But fortunately there is this forum. Thanks.

At thermal equilibrium, all molecules in a gas mixture have the same kinetic energy, so the lighter molecules (low molar mass) must be going faster. The kinetic energy may be the same, but low molar mass molecules are on average faster, and have lower momentum. Consider a mixture of CO2 and nitrogen at thermal equilibrium at room temperature (300 K). The average speed (vrms) of the N2 molecules is 517 m/s and that of CO2 molecules is 412 m/s. The CO2 molecules have higher momentum than the N2 molecules. Consider now an eddy in that gas mixture and continuous axial flow out of that eddy. It is a coherent vortex like the Red Spot of Jupiter. The axial flow should …

I don't believe in PMM's, but I'm trying to understand the physics of why the capillary and water mill PMM doesn't work. Can someone explain it to me in terms of "energy". Here was my explanation: Nature is always trying to achieve the lowest state of energy. If water overcomes gravity due to capillary action, that means that the intermolecular bonding of water to the glass surface (coupled with surface tension) achieves a lower state of energy than gravity alone. That being said, why would the water suddenly succumb to the force of gravity after the siphon? Capillary action is the lowest state of energy for that system, so succumbing to gravity later would actua…

So I'm not too sure what I'm doing here. I want to know how many photons there are in the given wavelength of "light". I have been digging for about two weeks in spare time. I am learning about plants and lighting and trying to make a project to build a light tailored to plants needs. At the moment I need to find out how to get total about of photons that are produced by a given light. Terms I know "of": mole (unit) einstein ( unit) Irradiance "PAR"and "PUR" plus some others I have some background in electronics and engineering as this is what i am going to school for. just two days ago I learned the differences between optics for the human eye and measureme…

Ok. I admit this is potentially VERY stupid, but I'm curious. From the Math I've done (more accurately let http://pacer.calpoly...cer/gforce.html do for me) a cylinder with a diameter of 60m (r=30) rotating @ 6rpm would produce 1.13G of centripetal force. If this cylinder was horizontal to the ground and one stood in this cylinder (assuming they were strapped in until the unit was up to speed) then they would experience 5 seconds of 2.13G decreasing to .13G followed by 5 seconds of returning to the 2.13G in a continuous cycle. While this alone would be an AWESOME experience, what would happen if one chose to jump? While they could theoretically leap almos…

I want to consider an idea for a rock mine operation to generate electricity for 10 or more years. There's a constant row of trucks that dump loads off a cliff about a 100 foot drop to a lower level. Would it be possible to build a chain driven tower with huge buckets on the chain drive that are spaced apart around the chain drive so that each truck dumps its huge load into a shoot that slides rock into the bucket at the top of the cliff, and about 7 full buckets would be full at all times on the desending side (empty buckets would be returning on the other side), and the chain drive would be turning a drive shaft at about a steady 18 rpm (same as a large wind turbin…

Hi everyone, I joined recently and I'd like to share some things I've written with you. I think they might be of interest to some people. This is the investigation I did for my final A level year. I was comparing the Kutta-Joukowski model of lift for thin aerofoils to experimental results. They fitted well (with 70% accuracy) but I had a few problems doing this investigation. Firstly in interpreting the Kutta-Joukowski model itself. The literature I read (and MATLAB model I used to design the aerofoils) took different mathematical approaches so it was difficult to piece together exactly how the model was meant to work. In the end I think I ended up creating an exp…

Today, in a test, I got the following question. State the factors on which the magnetic field due to a current carrying straight conductor depends. My answer to it is that magnetic field is directly proportional to both current and length of the conductor. But, my classmates answered- Magnetic field would be directly proportional to current and inversely proportional to the distance between the point and conductor. Now, the reference of a point in second answer seems incorrect because the question asked the factors affecting the magnetic field of a straight current carrying conductor not the factors affecting the magnetic field at a point? Am I right. Wouldn't …

I suppose this is a question on terminology. I see we have a page dedicated to relativity, but we seem to have a page dedicated to classical physics. Relativity is part of physics, it is a physical theory in itself. But it is also a classical theory, in that it does not take into account the Uncertainty Principle. So what is this subforum dedicated to mostly... Newtonian Mechanics perhaps?

What is heat? (i). Potential energy (ii). Kinetic energy (iii). The state of an individual particle/wave (iv). The state of an individual atom (v). The state of a collection of particles/waves (vi). The state of a collection of atoms, ie, a body (vii). Something else

I would like to hear your opinion, if this possible, in the following paradox: here

well to begin with the fundamental definition of work and energy,i found a flaws in one energy is capacity of doing work work is the transfer of energy that takes place under the effect of force,in the direction of displacement vector potential is the ability of doing work but the working element may not be at action at present firstly how is energy different from potential? secondly work done by magnetic forces is zero but there is energy involved which counters the above definition?