Center of mass equation help
so for the center of mass of an object.. x = (m1x1 + m2x2 + ...) / M total y = (m1y1 + m2y2 + ...) / M total how come in this equation the denominator is the total mass of the system? It seems like it...
View Articlewhat is "surface leakage"?
when talking about the conductance of glass or some insulator, i often hear that no current will be read going through the glass; rather, if i do read anything on my multimeter, i have been told that...
View ArticleElectrothermal Ramjet
Time to propose another crazy idea: the electrothermal ramjet. I was reading about Project Pluto today. I find it interesting that there is no combustion involved; just the compression of air then the...
View ArticleStrong Steel wire but an elastic spring? Why?
The steel wire can withstand strong tensile stress, but when the steel wire is being coiled into a spring it can be an elastic spring. Why is this? Can this be proven mathematically?
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Incompressible fluid acquiring momentum
Suppose we have the set up shown in the thumbnail, in which an incompressible fluid moves from left to right, trapped by converging streamlines. The rate of acquisition, F, of momentum by the fluid is...
View Articlewhy is there cold wind?
So awhile ago I was thinking about wind. Sometimes wind is hot but when I think of wind I usually think of cold wind. Wind seems to be fast moving particles and I know based on the kinetics theory of...
View ArticleQuestion about the collision of two objects (points) in space
Hello. I am new to these forums. I don't really know if this is the right place to post this, but here it goes. I was thinking, what If there were two bodies (represented by points) in space (two...
View ArticleWhen the Lagrangians are equals?
Im not very good with english, it isnt my native language...., but Im going to explain my question.... Im reading the first book of Landau's series ,its about clasical mechanics. In the second...
View ArticleFerromagnetic resonance oscillating field strength
Hello. What oscillating field strength, in tesla, is required to cause the magnetization vector of a ferromagnetic material to precess with a fairly large angle at its resonance frequency? I can't find...
View ArticleDeflection of an elastic curve
Hi: In mechanics of materials. I learned that the deflection of a beam can be characterized by its elastic curve which is the deformed neutral axis. But I am bothered by the fact that, if two end of a...
View ArticleFind acceleration component to hit target in 2D plane
Hi. Me and my dad (math teacher) are having some trouble finding the answer to a seemingly fairly easy problem. It is somewhat similar to projectile trajectory math but with the difference that the...
View ArticleMirrors and image formation..
Hi! I have two questions: 1) I'm a little confused about image formation. Suppose there's an illuminated object place in front of a mirror. The object has a rough surface causing a diffuse reflection...
View ArticleMechanics~polar coordinate & radial and transverse component
http://www.answers.com/topic/radial-...rse-components From the above link, 1) e θ is a unit vector perpendicular to r in the direction of increasing θ. Where is the direction of increasing θ? Is that a...
View ArticleFerromagnetic resonance magnetic strength
Hello! Can you use ferromagnetic resonance to manipulate the strength of magnets? If so, by how much? i.e. what percent decrease in magnetization can be achieved?
View ArticleCalculate forces acting on liquid film
Dear all fellow physicists, I am struggling with the following fluid mechanics problem: considering a liquid film in an "equilibrium" position between two plane walls, I am trying to define the forces...
View ArticleHelp about node calculation in stainless steel
Hi, someone can help me how calculate the nodes position in a vibrating stainless steel tube, from first harmonic to sixth harmonic Thanks
View Articlei don't understand gauss's law for sheet surfaces
hi all, gauss's law states that for any surface, the total electric flux coming through an open surface is always q/ε0. okay.. i understand this... so for a sphere.. the simplest case......
View ArticleHeat and space
A mass of gas has its molecules moving. (Say in a jar) Another mass of gas has its molecules moving faster. This gas is hotter than the first one. So, heat is motion of molecules. Now, I take this mass...
View ArticleRelating absorbance wavelengths and refractive index
Dear All, thank you for your attention. I am a Biologist and I was wondering if it is possible to translate absorbance λ values into a refractive index value? I found out about the sellmeier equation...
View ArticleOptical rotation and linear basis set
If I have a 45 degree linear polarized light which I then circularly polarize using a 1/4 wave plate and put this through an optical rotary crystal and then using the equivalent 1/4 wave plate but in...
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