Moment Definition and 1000 Threads

Looking at the image below, we have the function z^2=\frac{r^2}{a} yrevolving about y-axis. We know that y goes from 0 to "a". We also know the mass of the object (of uniform density). Do you think is my procedure correct? Do you get the same result?

Do mono-nuclear molecules have dipole moment? If yes then, what type of dipole moment? why do they have (or do not have) dipole moment?

Hi, I am a bit confused about the units of MI...I read that MI of rectangle is b*d^3/12,so unit is mm^4..Also i read in wiki that unit of MI is kg.mm^2... Both are correct,but why this difference is?

Hello, I can't find the formula for bending moment calculation of continuous tapered beam. the cross section is I (H) form, where web is 179.5 cm flange is 67 cm, web thickness is 1.5 cm and flange thickness is 2.5 cm. And this beam changes its height to 89.7 cm all other dimensions is the...

1. Material 2. Questions: a) (pink) Why does the author use two different values of inertia for the same slender rod ? The Attempt at a Solution [/B] a) I could assume that 1/3 is holding it at the end and 1/12 is holding it in the center. But it's not interchangeable because if I chose 1/3...

Homework Statement What is the moment of inertia round the axis of a cylinder length L, mass M and a linear distribution of mass with the radius R, zero at the center. Homework Equations Moment of inertia: ##I=mr^2#3 The Attempt at a Solution The density ρ=kr. what is k? the total mass is M...

Homework Statement Calculate the moment of inertia of a cube of mass M and edges d round an axiz, z, that passes in the middle. Then calculate around an axis parallel to the z axis and passing on one of the edges Homework Equations Moment of inertia: ##I=\int r^2dm## The Attempt at a...

Homework Statement The profiled steel I above is topped by a " profiled C ". Determine the moments of inertia of the structure composed by the axes central x and y through its geometric center C. Picture representing the problem: Homework Equations Profiled C and I information: The Attempt...

Homework Statement For F = 70 lb, compute the combined moment of the two forces about (a) point O, (b) point C, (c) point D. The moments are positive if counterclockwise, negative if clockwise. Homework Equations M = F d , M = r x F The Attempt at a Solution [/B]

Homework Statement Two particles of mass m1 = 14 kg and m2 = 24 kg are connected by a massless rod of length 1.4 m. Find the moment of inertia of this system for rotations about the following pivot points. Assume the rotation axis is perpendicular to the rod. A) center of rod B) end of m1...

Homework Statement Kepler’s 2nd law of planetary motion says that the radius vector drawn from the Sun to any planet sweeps out equal areas in equal time intervals. By considering the small area swept out by the radius vector in time dt, show that \frac{dA}{dt} = \frac{L}{2m} , where L is...

Homework Statement Three particles, each with mass m = 0.5 kg, are fixed on a uniform circular ring of mass M = 2 kg, radius a = 0.6 m and centre O, to form the corners of an equilateral triangle. What is the moment of inertia of this system? Homework Equations I = Σma2 The Attempt at a...

So the following question is attached (There is another thread with the same question but no solution to what I am asking on there) Now according to several solutions, apparently IYZ is equal to 0, and they reason this by saying that the geometry is symmetrical. However when looking at the...

Do bending moment and shear forces are dependable on a beam's cross sectional area?

Homework Statement Here we have two electrons rotating around z axis with angular speed w in a circle of radius R. They are on the same straight line (have difference in phase π). Find the magnetic moment. Homework Equations Magn. moment m=(1/2c)*∫dV [ r j ] The Attempt at a Solution Current...

Homework Statement An OAB pipe is embedded in O. A cable BC = 1000N and F = ( 0,-f , 0) act on B. Question: Determine the magnitude of the force F as the resultant moment about the axis OA is canceled. Picture in attachment: Homework EquationsThe Attempt at a Solution O=(0 0 0) A=(1.5 0 0)...

Homework Statement The landing gear of an aircraft is composed of a main leg OA (with a weight including the wheel is 1000N to G) and two secondary links BC and 50cm long each CD. The DC link forms an angle θ of 30 degrees with the vertical. a) Add the rotational equilibrium equation with...

1. The problem, I have a beam 9000 mm in length. assuming a x-coordinate system: supports are at the x= 1500, x= 4500, and x= 7500 positions. there's a uniformly distributed load (let's call it w) through the length of the beam (from 0 to 9000mm) Solve for the MAXIMUM moment. This would be much...

Homework Statement Stress = 320 MPa Max Elastic Moment = Stress*Z Max Plastic Moment = Stress*S Solve the maximum moments and compare the % increase Beam is an I beam with dimensions: (b and d) Top Flange = 25*10 web = 10*180 Bottom Flange = 200*8 Homework Equations see above The Attempt at...

Homework Statement What is the Moment of inertia of rod about an axis inclined? It is given as ## \frac{ML^2sin^2θ}{12} ## but how? Homework Equations I know MOI for axis passing through center along y-axis as ## \frac{ML^2}{12} ## The Attempt at a Solution Shouldn't it be ## \frac{ML^2}{12}...

Hello, I've been having some trouble with a paramagnetism problem from my Statistical Mechanics class textbook (F. Mandl, Statistical Physics, 2nd edition, p. 25). The problem is as follows 1. Homework Statement 2. Homework Equations 1. The temperature parameter \displaystyle{ \beta =...

Hello - I've been trying to solve this for a little while, and feel I may not understand some core concepts required to solve the problem. If you have any ideas, please let me know! I would very much like to discuss how to solve this. I am trying to calculate the bend moment from a rotating...

Could somebody check if I have done this correctly please? 1. Homework Statement Draw the shell filling for oxygen isotopes and make predictions of their nuclear spin, parity, magnetic moment and electric quadrupole moment. Homework Equations Magnetic moment μ = gj j μN Electric quadrupole...

Homework Statement I need to calculate the position and magnitude of the maximum bending moment. Knows are: E=210GPa Homework EquationsThe Attempt at a Solution I've calculated the following: R1=33kN R2=32kN From the shear force diagram I know that at 2m from R1 at the concentrated load of...

Hi, I understand that magnetic flux is like electric current and will take the path of least resistance, but I really don't like the current analogy and here's one question where it doesn't help: Say you've got a piece of Ferro Iron where the magnetic moments are not lined up, you put a...

Firstly apologies for not typing this out - but I need the diagram. And I have no idea where to start. I 'think' most of it is correct. BUT - I have no idea what to do with the last part of c. I thought I could just double the energy. But I'm going to get a negative energy for the system...

Hi, Is there a way to derive the moment of inertia of a sphere without using the M of I of a cylinder? In other words, is it possible to find a sphere's from scratch? Please include a derivation in your answer, unless there isn't one of course.

What happen if you do the following version of the double slit experiment: In first sequence the right slit is open and the left is closed, and a number of electrons are sent through. Then the right slit is closed and the left is opened, and a new sequece of electrons are fired. After completing...

Hello everyone, I would like to ask a couple of questions which are related to electric dipole moment and electric field. First one: Let us assume that we have somehow a constant electric field. The obvious thing to say is that any material that contains a Net Charge ( moving one or not moving...

I've been dealing with the concept of moment this whole year, in statics/dynamics but I've never really completely understood it, just rather memorized it. What I think moment is: If some point on a body has moment, then this means it wants to rotate. So moment is essentially what causes...

I am calculating the all reaction forces in this beam. However, I want to ask: By taking moment about point B, why does the moment of the UDL become 15*7*5.5 instead of 15*7*4.5 Thanks !

how can we relate innermost stable circular orbits, keplerian, epicyclic, frame dragging precession frequency with dipole moment.

I have a question about body inertness. Is moment of inertia is unambiguous inertness characteristic?

Homework Statement Hi all, I just had a quick question regarding a problem that I have to write a lab report on. The problem involves solving for the moment of inertia of a system that involves a pulley with a hanging mass attached to a spool that turns a flywheel. The solution is supposed to...

Hi, I've been grappling with a calculation that appears to give me a good result, however my gut feeling says other wise. Could someone please check the layout and possibly confirm my final answer. Attached is the layout of the system. The system: -There is a long arm, d1+d2 is one link. then...

Homework Statement I am trying to work the moment of inertia for a) rotating rod, axis through the centre of the rod http://hyperphysics.phy-astr.gsu.edu/hbase/mi2.html#irod3 b) Solid cylinder http://hyperphysics.phy-astr.gsu.edu/hbase/icyl.html#icyl2 [/B] Homework Equations I = R^2 dM The...

Sorry to bring this question up again. @aridno provides a nice formula of the moment of inertia I about the centroid in https://www.physicsforums.com/threads/calculating-polygon-inertia.25293/ as: $$...

I have come up with a paradox: Ionic crystals, in which cations and anions form a lattice, seems to have total electric dipole moment! For example, consider a one dimensional example: ##+ - + - + - ... + - + -## In the above picture, a ##+## represents a cation and a ##-## represents an anion...

just picture what happens when you fill a 2 liter soda bottle with water (or any liquid) and try to pour it all out at once. it comes out in clumps. This means there will be competition, since all the water will try to escape all at once. the fact that there is competition means that there...

I had a discussion with my friend. He took an icecream stick and told me that if the stick was held horizontally the stick would break easily but if you held the stick vertically it would be difficult to break the stick. He said that vertically the moment of inertia is more. My question is that...

The first moment divided by the total mass is the center of mass. Now I know that a moment is a combination of a physical quantity and distance. So what is the First moment made up of? I know that moment of inertia is made up of mass times the radius (distance) squared.

Homework Statement The L-shaped bar of mass m is lying on the horizontal surface when the force P is applied at A as shown. Determine the initial acceleration of point A. Neglect friction and the thickness of the bar. (Sorry, don´t know how to get you a better picture) L...

Homework Statement See the attached image. Homework Equations ##T = 1/2 \omega^2 I## The Attempt at a Solution So ##I_1,I_2,I_3## are just the moments of inertia of the object with regards to the 3 axes. Right? OK, then I intuitively assume that the total kinetic energy must simply be...

Hello Everyone, A little question regarding the TDMs between two different electronic states of a diatomic molecule. If I am calculating the TDM from state A to state B, is it the same if we are calculating the TDM from state B to state A? Are these two transitions the same? Thank you so much...

Homework Statement for this composite object, what moment of inertia needs to be used if you were to sum the moments about the centroid of the object, \sum M=I\ddot\theta Homework EquationsThe Attempt at a Solution is it the sum of the I_zfor a solid sphere and a solid cylinder

Homework Statement Homework Equations ∑F=ma ∑M=Iα 3. The Attempt at a Solution I used the dynamic equilibrium formulas to find the tension. The tension helps me to find the acceleration of the block. Then, I used kinematics to find the velocity. But, I'm not getting the right answer.correct...

Homework Statement [/B] Statement: Find the principal axes of the section shown: The origin is on the top left corner. Homework Equations [/B] Centroid equations: Second moments of area: Mohr's Circle for I equations: Coordinates Centre Angle from principal axes: The Attempt at...

Homework Statement "a uniform steel rod of length 1.20 meters and mass 6.40 kg has attached to each end a small ball of mass 1.06 kg. The rod is constrained to rotate in a horizontal plane about a vertical axis through its midpoint. Find the moment of inertia of the ball-rod system." Homework...

A equilateral triangular lamina, has a moment of Inertia of I if the axis of rotation passes through the centroid of the triangle, perpendicular to it's plane. What is the moment of inertia of a regular hexagon(Again, through it's geometrical centre, perpendicular to the plane), provided that...

1) Problem: An individual holds a ball of mass 3 kg in his hand in static equilibrium. The biceps brachii attaches a distance of 2 cm from the centre of rotation of the elbow joint, and the muscle's line of action is directed at an angle of 115° counter clockwise from the forearm. The forearm...