Center Definition and 1000 Threads

I know that, i studied it, but i can't actually make a picture in my mind, i can't really figure out why, i mean the forces and the torques are the same no? What's the big deal? What am i missing?

Homework Statement The system shown in (Figure 1) consists of two balls Aand B connected by a thin rod of negligible mass. Ball Ahas three times the inertia of ball B and the distance between the two balls is ℓ. The system has a translational velocity of v in the x direction and is spinning...

Hello, everyone. This is my first post! Center of gravity does not seem like a difficult concept to grasp, but for some reason, I find it difficult to put into words. Would I be correct in saying: the center of gravity is a point on an object that represents the average position of an object's...

look figure (b) suppose that baseball deliver F through horizontal motion. imagine that the O point of the system is same line of F (+x is F direction) then before percussion, the angular momentum of the system is "0" because r and v of baseball are same direction (L = r x mv = 0) so after...

I have an i-beam placed horizontally and i want to apply 1 ton point load on its center. Now i will run a stress analysis on ansys on it and will get the displacement in the beam on the mentioned load. How will i know tht the displacement value i am getting is good or bad?

I've recently read that the universe is now estimated to be about 95 billion light years in diameter. This was based on what we now can observe (Hubble Deep Field for example), what is estimated to be seen with new technology (James Webb) and an estimate of what's beyond that which we can't yet...

Homework Statement why the maximum bending moment at the center is w(l^2) /8 ? Homework EquationsThe Attempt at a Solution shouldn't it be = 0 ? when we take the moment about the center , the reaction force at the left will generate clockwise moment , while the reaction force at the right...

With length contraction being ever increased while approaching the mass of a black hole singularity, how does one measure the distance to the virtual infinite contracting frames of reference of time and space /distance of the singularity? Related question : How can one measure the size of a...

Homework Statement Determine the angular velocity of the gear at the instant shown. Set v = 9ft/s and vc = 6ft/s. Assume counterclockwise is positive. Homework Equations v = w x rIC The Attempt at a Solution I tried solving this many times using va = v0 + (ω x ra0 ) and vb=v0 + (ω x rb0 )...

Why do we take the Center of mass to be on the right side rather than on the left? A uniform circular disc of radius 4a with a circular hole of radius 2a made in the disc. The mass of L is m and a particle of mass km is now fixed to L at the point P. The system is now suspended from the point S...

Hello all. I am working on a research project involving the Stark effect and its application in molecular guides and came across a bit of math in a paper that I don't understand. In this paper http://arxiv.org/abs/physics/0310046 there is an equation in the introduction concerning the electric...

If time does indeed come to a stop at the event horizon, how are we even able to observe it? Wouldn't it cease to exist to someone moving through time the moment time comes to a halt on the event horizon?

Hello Community My first post here so excuse me in case i posted in the wrong place. I basically have to write a paper in school about a physics topic. This includes creating graphs with independent and dependant variables and finding the slope. It should be something to complicated but also...

A quick question, I remember my professor said to use the center of mass for solving the classic loop de loop problem. For example, he wanted us to use the distance from the surface of the loop to the center of the object (instead of just from the loop to the surface of the block) for the height...

This example might be not very interesting, but perhaps helps to improve my understanding. Is a radially falling rod in free fall? Which frequency shift of light emitted at the ends of the rod would observers at rest at the respective other ends measure? Here are some assumptions. Please...

Is there a relatively simple way to find the center of gravity of an object? I need to know to see if my model rocket has a high center of gravity. The bulk of he weight is in the bottom.

Homework Statement We have a rod (length L, mass m) suspended at a point whose distance from the center of mass is a. 1) prove that (generally) there exist two values of a (a1, a2) for which the pendulum oscillates with the same period. 2) derive and explain: T = 2\pi\sqrt{\frac{a_1+ a_2}{g}}...

What kind of force acts in the centre of the Earth ? What is the intensity ?

Homework Statement If n ≥ 3, show that Z(D_n) = C(x) ∩ C(y). Homework Equations G is a group, g∈G C(g) = {h∈G: hg = gh } The Centralizer of g Z(G) = {h∈G: hg = gh for all g∈G} The center of G ∩ means the set of all points that fall in C(x) and C(y). Every element of D_n can be uniquely...

Homework Statement A circular rod has a radius of curvature R = 8.11 cm, and a uniformly distributed positive charge Q = 6.25 pC and subtends an angle theta = 2.40 rad. What is the magnitude of the electric field that Q produces at the center of curvature? Homework Equations E = kQ/r^2 6.25 pC...

I have learned that the gravity at the center of the Earth is zero. I guess its because it gets balanced as the force from all the sides are equal in magnitude and opp in direction. But several land forms throughout the world having different masses could cause a distortion which could make an...

I am preparing for a qualifying exam for my PhD program and am looking at some of the old tests from previous years (as supplied by the school for study/prep material). I have come across a deflection problem that has me stumped, and I might just be overthinking it. The problem:

Homework Statement Determine the center of mass in cylindrical coordinates of a cone with constant density ##\rho(\vec{r})##. (The cone is inverted, i.e. it's thinnest point is at ##z=0##.) Homework Equations ##m=\int\int\int_C \rho r \, drdzd\theta## ##\overline{r}=\int\int\int_C r\cdot r\...

I want to prove the formula of regular dodecahedron's volume. For this, I need to split the dodecahedron to 12 pentagonal pyramid with the same size. However, I don't know how to determine the height of those pentagonal pyramids. Any references I had encountered involving either golden ratio or...

Four 9.5 kg spheres are located at the corners of a square of side .60 m. Calculate the magnitude and direction of the total gravitational force exerted on one sphere by the other three. So, essentially my question is, why can I not use center of mass of the other 3 spheres to calculate the...

Homework Statement A square wire loop 12.0 cm on each side carries a clockwise current of 15.0 A Find the magnitude of the magnetic field at its center due to the four 1.30 −mm wire segments at the midpoint of each side. Homework Equations B = (μ0*I)/(4π)*(2a)/(x√(x^2+a^2)) The Attempt at a...

Do all stars in the Milky Way orbit the galactic center in approximately the same direction? Also, toward which Zodiac constellation is the Sun moving in its orbit?

Homework Statement A square wire loop 12.0 cm on each side carries a clockwise current of 15.0 A Find the magnitude of the magnetic field at its center due to the four 1.30 −mm wire segments at the midpoint of each side. Homework Equations B = (μ0*I)/(4π)*(2a)/(x√(x^2+a^2)) The Attempt at a...

Homework Statement can someone explain about the Fr acting at a distance 2b/3 from free surface firectly beneath the centroid of the surface ? Homework EquationsThe Attempt at a Solution does the author mean the center if pressure ( point where the FR acts) of the completely submerged plate...

Homework Statement System S is static and is comprised of 3 identical metal pipes A, B and C which are placed so that A lays ontop of B and C. B lays into the y axis. The length of the pipes are orientated parallel with the z axis. The outer and inner radius of each pipe is (Outer : 0.51m)...

Homework Statement the buoyancy force i found id 0.751(1000)(9.81)(0.5x0.55x0.96) = 1945N , i also found that the center of gravity of submerged portion is (48/3 , 55/ 30 = (16 , 18.3) , how to find the center of buoyancy ? is the cnter of buoyancy acted half of the submerged portion , which is...

Hi , I came across a problem ,I've search a lot but couldn't exactly find the solution. here is my problem: suppose there is an image ( I call it IMG_A),place IMG_A in the X-Y plane , put a mirror cylinder at the center of IMG_A. what we see in the cylinder mirror is a deform image (I call it...

Homework Statement To determine the location of her center of mass, a physics student lies on a plank of weight 100.0 N and length 2.5 m supported by two scales 2.50 m apart. The left scale reads 420.0 N, and the right scale reads 210.0 N. (Note: Don’t neglect the weight of the plank when you...

Homework Statement why the floating body still stable when G ( center of gravity ) is above the B ( center of buoyancy)? Homework EquationsThe Attempt at a Solution in my opinion , the statement is worng , because when G is above B , G has the tendency to move downward , causing the object to...

As far as I know in a system of particles or a body there is a point that behaves like all the forces on the system are applied at this point, but are these forces really applied in this point? Can you explain please, I thought at this and I arrived at the conclusion that these forces aren't...

a related thought experiment to a tunnel through Earth through which a person falls to the other side, is what if it was a pendulum falling through the planet? first, a pendulum is at 90 degs to the G field; 2nd, as soon as the pendulum BEGINS to fall through, it is in free fall, and it will...

I would like to locate the center wavelength of a FBG notch filter in MATLAB, but I'm having trouble getting an answer within 0.01nm of the correct wavelength. So far I've tried using a quadratic fit with MATLAB, but that is too dependent on the amount of data points to the left and right of...

Greetings all, In my quest to imagine the ultimate sportscar, I began to wonder about the following: Certain cars are All Wheel Driven (AWD) and they do so via a Center differential delivering power to both axles. Amongst those cars, some have fixed Torque Bias/Split Ratio, which doesn't alter...

Homework Statement A person with mass m is sitting on one end of a lifeboat of uniform density. Mass of lifeboat is 3m. The person then walks a distance of L to the other side of the lifeboat. Which of the following statements best characterizes the motion of the lifeboat? " The lifeboat...

Hello! (Wave) I want to find the center of $S_n$. $Z(S_n)=\{ c \in S_n: cg=gc , \forall g \in S_n\}$.Every $c\in S_n$ can be written as a product of transpositions, $$c = \prod_{i = 1}^r (1\, m_i)$$ for some $r$ and some sequence $(m_i)_{1\leqslant i \leqslant r}$, right? Doesn't this imply...

My objective is to make a lc circuit that will have a potential difference across the inductor that is lower than that of the capacitor. A spark gap must also be used. Will this work and will the resonant frequency be the same as if it was wired conventionally?

Hello! (Wave) I want to find the center of $GL_n(\mathbb{R})$. $Z(GL_n(\mathbb{R}))=\{ c \in GL_n(\mathbb{R}): cg=gc \forall g \in GL_n(\mathbb{R}) \}$ I have thought the following. Let $c \in GL_n(\mathbb{R})$. Then there is a $b \in GL_n(\mathbb{R})$ such that $cb=I$ where $I$ is the $n...

https://losc.ligo.org/events/GW150914/']The[/PLAIN] LIGO Open Science Center has released data from the gravitational wave detection along with a tutorial going through some typical signal processing tasks on strain time-series data associated with it. GW150914 Data Release From the tutorial...

I've been thinking for awhile now, and I still don't understand how these types of black holes form, since they can't form by conventional means.

Homework Statement A heavy ring of mass m is clamped on the periphery of a light circular disc. A small particle of equal mass is placed at the center of the disc. The system is rotated in such a way that the center moves in a circle of radius r and with a uniform speed v. Find the external...

here from time 0:53 to 0:58 velocity at center would be more than or approximately equal to zero .I want to ask why approximately zero why not zero?

How do we know that the nucleus is at the center of the atom? I know about the Geiger/Marsden experiment and also of its results. They observed a few α-particles scattering almost at 180°. Hence they concluded that there must exist a high density, positively charged "center" in the atom. But on...

I was reading about the ISS earlier, and this question came into my mind, and I can't seem to decided how this actually works. Here's the set-up: Say I have two masses stuck together (m1 and m2) to form a mass M in orbit around some planet (like the ISS, and some large space capsule that is...

Homework Statement pls refer to photo 2 , (circled part) How to transform equation in 3-20 to become equation in 3-22a ?Homework EquationsThe Attempt at a Solution i have tried in photo 3 , yet can get the same form as in 3-22a . In step 2 , i divided the y_p with Fr

I'm playing a game, From the Depths, that let's you build your own helicopter blades (and put them on ships that you build) and program in LUA. I did some searching and found: Calculating the Center of Thrust on Multirotors | Flite Test Currently, there is no way to tell how much lift a given...