Shape Definition and 613 Threads

hello i came across an old article about crystalline shape of AEC2 receptor that is been some how associated with covid-19 my question dose knowing the crystalline profile of protein receptors some how can help with finding a better aid against this kind of outbreaks and how crystalline...

Using real science we can extrapolate what hull shapes could be used, assuming we actually did have high thrust constant acceleration drives (we don't because it requires energy/mass ratios that tend to cancel each other out). So what shapes? Pill capsules are ideal for crewed vessels. Even...

To find out what the induced loop current was i used the formula: V=R×I To find out what the value of V was i used the formula that links electromotive force (fem) to angular speed: Fem=ω×B×A The only thing that's missing is the loops area but considering that it's a semicircle and that the...

Homework Statement:: Violin String Shape Functions Homework Equations:: Violin String Shape Functions Hello, Is anyone working on violin string shape functions(Timoshenko Beam Theory)? It would be really helpful to my research if we share our knowledge on this topic. Thank you

Answer given is " The molecule could be trigonal pyramidal or T shaped, but could not be trigonal planar." I am confused as the shape of BF3 is trigonal planar...

no need of equations

Is there a plausible way for shapeshifters like Odo from Star Trek Deep Space Nine to exist? Obviously, our shapeshifter couldn't recode its own DNA and change its phenotype in moments. But what if Odo were a swarm--or metaswarm--of microbots ? How could they be coordinated? Would they...

Hello all After a lot of support from people like Dr.D, mfig and collinsmark I have finally understood the concept of Centriods and Centre of Mass. I am now trying to understand how a uniformally distributed force and a non uniformally distributed force acts on a shape. If I had an oddly...

Hi! First of all, mention that this is not a "homework" problem in the sense that no teacher ever gave it to me or that I have the obligation to do it. It is a question that came to mind when repasing the theory done in class and though interesting. I still post it here because I suppose that...

My approach was that I consider the pressure of cross section A first Pa= P + dgh Now by writting Bernoulli's Equation between the cross-section A and the opening : $$ Pa + 2dgh + 2dV^2/2 = Pb + 2dV'^2/2$$ Where Pb is the pressure of the opening which is equal to the atmospheric pressure...

Hi PF! Suppose a 2D rectangular channel with wall-normal perpendicular to the downward gravity force ##F## rests is static equilibrium. What shape would the liquid take? Looking at the equations of motion, I think the following would have to be satisfied: $$\frac{d P}{dy} = -\rho F\\ \Delta P...

Do you have any information's about how to calculate the bias spring or the Force needed ? the current necessary to heat the SMA spring for a 4mm stroke ? Thank you

As we know that liquids(same) at same height exert same pressure because of height difference but as I have a question in which there are some figures In which the (d) part lower part is extended horizontally,so by common sense the pressure in horizontal direction should increase But why at...

Hello all, I hope this post is in the appropriate thread. Would anyone have any insight on a method to quantify deformation of a shape? For example, I attached two images of a white shape of interest at the center (one deformed and one undeformed). I'm trying to develop a metric/parameter...

Mass causes space to change shape, and that's what we see as gravity. But does space move when it changes shape? If yes, relative to what?

I investigate the damage to the metal surface with box-counting method and some surface images give a convex multifractal spectrum f for a result - which is also widespread in the literature, but some other surface images form a concave multifractal spectrum. Not much information is available on...

I've attempted this question, but the answer seems to be incorrect. Here's my workings: ##I=\int y^2 dm## - standard equation ##dM = \mu * dy * x## - take small slice and find mass of it ##x = 4y-16## - convert equation in terms of x to sub in later ##dM = \mu * dy * 4y-16## ##I=\int y^2 \mu *...

Hello, A light pulse moving bouncing between two mirrors (top and bottom) follows a vertical straight path w.r.t. to an inertial observer at rest relative to the mirrors. However, a moving inertial observer see the light pulse move in a zig-zag path as it bounced back and forth between the...

I read about semiconductor laser and its beam shape is conical with 50' of dispersion angle. But for me, it is hard to accept that it is conical because every single drawing I see is rectangular and the plan that laser going out is also a plain, not a hole. And this is the picture I saw...

If Jupiter is made of gas, how can it maintain its spherical shape without being contained in a spherical shaped container?

Summary: Rotate a shape back to it's original position with the least amount of rotations. Lets say you have a cube. It's starting rotation is (0,0,0). It can be rotated on each axis ( x,y,z ) no more than once each by 90 or -90 degrees (rotation can also be skipped for any axis). The shape...

To be honest i don't know from where to start. I know how i can test the stokes theorem if i have a cylindrical shape and a cylindrical vector or spherical vector and a spherical shape but here I am out of ideals. The first thing i tried was to compute the left part of the stokes theorem but i...

Hello! For dielectric slab waveguides, starting from the field expressions, it is possible to draw the Electric field corresponding to a specific mode, showing its (possible) zeros inside the core and its exponential decay in the cladding: A Google search can provide plenty of images like...

Homework Statement A drop of water fall towards the ground with initial mass [m][/0] and radius [r][/0] (assume the initial shape of that water drop is sphere). the air resistance is F=½.ρ.A.[v][/2].C (C is the drag coefficent, A is the area that the air contact with the water drop and ρ is the...

I know the basic equations of a solenoid carrying a current, the consequences of having an iron core inside one, and how that derives from Ampere's law. But these suggest that the only figure of merit is the cross section area of an iron core and the solenoid, not their shape. Thinking in more...

Hello all: I was wondering what is the shape of the plasma at Nif ,is it spherical ? I start to wonder that it may be spindle shaped ,or fusiform shaped . Best H

1. A closed cylindrical vessel filled with water (at room temperature) contains a small air bubble of normal pressure and volume ##V=1~{cm}^3## inside in it.The cylinder is then started to be rotated slowly with a small angular acceleration in a complete weightlessness (at a space station)...

I am trying to understand how fluids form particular shapes when put on a solid. In the two figures,what are we taking as a system for the forces? How the resultant of the forces influences the shape of the different fluids?

Homework Statement Hey, just wanted to ask a quick question about how to find the moment of inertia of two rods (of equal mass and length) attached together in a T shape (the axis is at the bottom of the vertical rod). My calculations got the correct result but I just wanted to check whether my...

The Oort cloud is often drawn as a sphere. Everything in it orbits the sun in circles or ellipses. Since the shape is not a disk, collisions are expected. Why hasn't the Oort cloud converged to the more stable, collision-free, disk shape?

I would like to simulate a simplified version of this phenomenon: where I will assume that the viscosity is zero and the liquid can therefore swirl around "laminarly" forever according to some velocity profile that I specify. How can I calculate the shape of the surface, at least in this...

This is an inquiry about some of the details of the bending of the trajectory if a photon by curved space-time (S-T) from the perspective of general relativity (GR). The environment in this scenario contains a black hole at its center, a photon passing by the black hole a km above the event...

What is the shape and geometry of BrF3?

Homework Statement The rigidly connected unit consists of a 2.5-kg circular disk, a 2.8-kg round shaft, and a 4.2-kg square plate. Determine the z-coordinate of the mass center of the unit.Homework Equations ∑zm/∑m The Attempt at a Solution Circular disk: mass = 2.5 kg z = 0 zm = 0 Round...

Hello! I am going to talk here about a real scalar field for simplicity. If we have a Higgs-like potential for a real scalar field, the graph of the potential looks like a section of a "Mexican hat", with a bump at 0 and two absolute minima at, say, ##\pm a##. This is the plot I see in any book...

Homework Statement **I couldn't get my specific picture to copy but here is one that is the same except, 2.6b=1.7b and 2.0b = 1.3b** Determine the x- and y-coordinates of the trapezoidal shape. (X bar, Y bar) = Homework Equations X bar = ∫xdA / ∫dA Y bar = ∫ydA/∫dA The Attempt at a...

What is the shape of very massive stars? Are they simply spheres or something else?

It's been a couple of years since I've posted here, and am trying to get back into learning SR. I wanted to start with a general question: You often hear the phrase "we are moving through time". I've also seen space-time described many times as like a block. Another way I've seen it described is...

1. Two coaxial rings of radius R=10 cm are placed to a distance L from each other.There is a soap film connecting the two rings(that looks like a cylinder which have different radii with z coordinate. (The rings lie in xy plane)).Derive a differential equation describing the shape r(z) of the...

I was wondering if it was possible to create any shape of magnetic field. If yes, what would it take to do so?

Hello. The curve y = x2 is a parabola that looks like this: I have a shape Square that looks like this: What I am noticing is that if I consider the equation y = x2 and also the shape Square, I find that there is no connection between them but the equation y = x2 is pronounced as x-square...

I have been looking around for information on how to find the perimeter of an odd shape, but I can't find any explanations that seem to fit because the given shape is partially rounded. I already know the answer is $$16 + 2\pi$$ but I am unsure how they came to it. I'm guessing they get $$16$$...

Homework Statement The half thin steel plate has a radius of 4 meters and a surface density of (3+r) kg/m^2, where r is the radial distance from the origin. Using calculus, find: A. its area B. its mass C. Its center of mass with respect to the origin shown, D. It's rotational inertia about the...

My understanding is that the amount of heat energy a parabolic reflective surface generates is not the volume of surface area of the mirror, but essentially the volume of surface exposed perpendicular to the suns rays. This effective surface can be also described as the area of shadow that is...

What is the highest efficiency (electromagnetic) radiator shape? Meaning, a shape with the highest radiated power/volume (radiated power is in this case dependent only on surface area and how much of the radiation is reabsorbed by the radiatior)

I'm working on an audio synthesis project and I need an equation that can create these lines: That is, I would like an equation that describes a line that always passes through (0,1) and (1,0), and has a single coefficient parameter that can be varied to create functions of intermediate...

Hello everyone, I don't normally come to Astro/Cosmo forums, but I stumbled upon a discussion between a mentor and a PF member here, which involved explanations on the geometry of the universe: difference between boundless vs unlimited, 2-torus vs 3-torus, why are tori boundless, etc. This got...

Hi, a fast question... I was having somekind of a discussion, and I actually hit a dead end to the way I could explain my statement. I believe that after the Higgs Mechanism and SSB, the resulting potential of the Higgs Field should no longer be symmetric to rotations : I am saying this because...

I just went on a Japan trip. In the airplane, besides throwing up my ball and phone, I was doing a little bit of studying. While the plane was in takeoff, in the middle of flying, and landing, I noticed how the wing positions changed. I already know how takeoff works. It works when the plane...

Homework Statement Homework EquationsThe Attempt at a Solution Substituting x = ## r \cos{ \theta } ## and y = ## r \sin \theta ## into the equation y = 3x +2, I got r = ## \frac { -3 \cos{\theta} \pm \sqrt{ 4 – 31 ( \cos{\theta} )^2 } } { 10 ( \cos{\theta} ) ^2 – 1} ##Plotting...