Moment Definition and 1000 Threads

In the picture the question marked spot is confusing me. Should the MI be calculated in this ugly way? That we do not consider the points in between and on dx! Why only x is taken as the distance? You may say take x+dx, resulting dx in the exapnsion and the dx from the mass to square and being...

Homework Statement https://imgur.com/a/AGJaN It's a project so not a textbook question. The Attempt at a Solution Given in imgur picture. [/B] I'm looking to solve for C. The problem is actually a trailer with 3 axles but simplifying here as 3 fixed points where the wheels would be. The...

When the aminoacid environment were changed with adding OH or etc., Aminoacid N terminal were affected by H amount and in determined pKa, they loose hydrogen from N terminal. NH3 goes Nh2. My question is related to this. While this event occur, how change dipole moment of this terminal? Electron...

For a 4x4 beam 12' long supported by 4x4 8' tall colums I need to calculate the moment around A and B and the vertical forces at A and B based off the point load which for discussion purposes is in the middle of the beam but could be anywhere on the beam. Does anyone know the calculations? I...

Homework Statement A round bar .125mm in diameter , is to be used as a beam. IF Youngs modulus For the material E=200x103N/mm2 and the stress due to bending is limited to 17.5N/mm2 A) Maximum allowable bending moment B) the radius of curvature at the point of Maximum bending moment Homework...

Greetings! Can someone please help me figure out how to calculate the second moment of area for a hollow isosceles triangle? Is there an equation available somewhere? Or can I simply subtract a smaller triangle from a larger one, using the equation I=bh3/36? (so I= b1h13/36 -b2h23/36) Also, is...

Time can be divided three ways Time in the future Time in the present Time in the past We are living in the 'present'. My question: how 'big' is this present time? It might help if you think of a pen placed on a white sheet of paper. The pen represents our present time. The white space above...

Homework Statement I was learning how to calculate moment of inertia on Youtube, and I'm confused about when to use 1/2 mr2 instead of mr2. This video says that he used 1/2 mr2 instead of mr2 because the cone is solid But in this video, while he was calculating a solid sphere, he used mr2...

Homework Statement Kindly see the screenshot attached below for the question. Homework Equations I=1/3ML^2 1/12ML^2 The Attempt at a Solution In the solution to this question, the moment of inertia of the hands (when outstretched) is taken to be 1/12ML^2 (combined). I think that it should be...

If two gears are joined to together, how are their moment of inertia calculated? Separately or combined?

The spin magnetic moment of a charged, spin-1/2 particle is $$g \frac e {2m} \frac \hbar 2$$ where g is the g-factor (2 for any particle in tree-level approximation, 2.00231930436182 for electron), e is charge m is mass ##\frac \hbar 2## is spin But with zero mass this expression does not make...

Homework Statement A disk of radius R has an initial mass M. Then a hole of radius (1/4) is drilled, with its edge at the disk center. Find the new rotational inertia about the central axis. Hint: Find the rotational inertia of the missing piece, and subtract it from that of the whole disk...

ok so for concentrated loads the sheer diagram is constant meaning are straight horizontal lines and the bending moment diagram is linear. when there are evenly distributed loads sheer diagram is linear and bending moment diagram is quadratic. I am thinking that when there is a load distributed...

Homework Statement [/B] Consider the hydrogen atom in the 42F5/2 state. Take into account the effects of finestructure (spin-orbit coupling). (a) Write down the spectroscopic notation of the state that the 42F5/2 is degenerate with, in the absence of an external magnetic field. (b) Calculate...

1. Homework Statement I have problem solving the bending moment and shear force of a conduit with a curve end. The conduit is lifted in the mid-air with 2 slings and assume it is in equillibrum. I have attach a drawing for reference. Homework Equations What i know, there is a UDL somewhere...

How would you calculate the induced magnetic field B at some distance R from a bar magnet, given the magnetic moment of a magnet? (In general)

Homework Statement Okay, so this isn't so much a problem as a design issue while following an example given in a book. (Relevant material is here: http://www.aero.us.es/adesign/Slides/Extra/Stability/Design_Control_Surface/Chapter%2012.%20Desig%20of%20Control%20Surfaces%20(Elevator).pdf ) Now...

Homework Statement A car accelerates from rest on a horizontal surface. The engine provides a torque of τ = 200 Nm on each of the two front wheels. Each of the four wheels on the car weigh m = 15 kg, have radius R = 0.35 m and can be considered solid, uniform discs. The rest of the car (not the...

A girl is climbing up a set of stairs and has her femur horizontal. Her thigh weighs 12 pounds, acting at a center of mass 15 cm from her hip joint. She places 50 pounds of weight on the lower portion of that leg, vertically through her knee. Her gluteus maximus is applying a force directed 30...

I have some serious confusion regarding the title for the following issue . I have read on plethora of forums and sites, giving the explanation of why hollow tubing is stronger than solid rod of the same dia or weight by justifying as to why it bends the least . This makes me ponder ! Stronger...

I have proved (8.1). However I am trying to prove that ##\bar{X},X_i-\bar{X},i=1,...,n## has a joint distribution that is multivariate normal. I am trying to prove it by looking at the moment generating function: ##E(e^{t(X_i-\bar{X})}=E(e^{tX_i})E(e^{-\frac{t}{n}\sum_{i=1}^n X_i})## I am...

Homework Statement A spherical shell of radius R has a surface charge distribution σ = k sinφ. Calculate the dipole moment of the spherical shell. Homework Equations P[/B]' = ∫r' σ(r') da' The Attempt at a Solution So I believe my dipole will be directed along the y axis, as the function...

Hi I am struggling with the following question. A cylinder of radius 20cm is mounted on a horizontal axle coincident with its axis and is free to rotate. A light chord is wound onto it and a 50g mass hung from it. After release the mass drops 1m in 12seconds. What is the moment of inertia...

Homework Statement Calculate the moment of inertia in the OO' axis of the following figure (image attached).Homework Equations The relevant equations are in the image, except: I = Icm + m.h2 (formula of moment of inertia to change the axis from the centre of mass to a parallel axis). The...

(Forgive me if this is in the wrong spot) I understand how tensors transform. I can easily type a rule with the differentials of coordinates, say for strain. I also know that the moment of inertia is a tensor. But I cannot see how it transforms as does the standard rules of covariant...

1. Homework Statement It is a part of the question in my homework and I extract this out just for the part i m confused(in the picture above) Homework Equations Moment couple=d*F [d is the difference in point of application (=sqrt41) or the perpendicular distance of the forces(=0) ?] The...

Homework Statement Homework Equations M=r x F = d * F (for moment couple) The Attempt at a Solution This is my attempt to the question, yet I have got quite a different answer from my classmates... (especially the moment by the 50N force couple) Can anyone point out is there anything wrong...

Homework Statement Find the magnetic moment of a crystal when placed (i) in a weak field at high temperature (ii) in a strong field at low temperature Homework Equations This is the last part of a question which I feel I have solved correctly up until this point. The mean magnetic moment I...

I was reading the statistical physics textbook and was really confused with the notation: I don't understand the last part of the section. Why is that \sum_{\sigma = \pm1} \sigma P(\sigma) equals to \left< \sigma \right>? And what does \left< \sigma \right> actually mean? Is it the average...

Is there a table of Electric Dipole Moments, ##\bar p##, for the Sun, Earth, Planets, Minor Planets and Moons?

Stupid question: I have the following pipe configuration: Working fluid = ambient air Pipe1 = 6 inch ID x 24 inch length Expansion1 = 2 inch length Pipe2 = 8 inch ID x 2 inch length Fan1 = assume 200 CFM @ 2860 rpm, 0.05 inH2O Contraction1 = 2 inch length Pipe3 = 6 inch ID x 12 inch length...

The Magnetic Dipole Moment for a Magnetic Field for a dipole oriented on the x-y axis is: ##\bar m = |m| \hat z## The Magnetic Field is: ##\bar B = \frac{\mhu_0}{4 * \pi * |\bar r|^5} * 3 * \bar r * (\bar m . \bar r) - \bar m * |\bar r|^2## Vector Potential is: ##\bar A = \frac{\mhu_0}{4 * \pi...

At what point will weight have a diminishing effect on increasing MOI with a given size remaining the same?

1. The problems: The questions are to find the x, y and z components of the equivalent MOMENT at point A in both diagrams. For the green block, I found the y and z components of the equivalent force at point A are -39.04kN and 15.48kN respectively. The Attempt at a Solution For the first...

Homework Statement I don't understand why the fixed end moment at AE is 10KNm ( clockwise) . Homework EquationsThe Attempt at a Solution Forger about the sign convention here , i have the resultant moment = 10KNm , which ic clockwise , why in the 2nd picture ( SFD and BMD part) , the moment...

Ok, so this is an undergraduate level question probably but consider this R. C. Hibbeler's Textbook on Mechanics of Materials says this about thrust bearings and smooth journal Bearings : In other words, it says nothing about reaction moments. Now this chart has other 2D connection types...

I'm working this problem for my math stat class. Here is what I have for it. First of all, is this the correct method for finding MGF? I thought it was but I don't understand the answers I am getting. How do I determine my values for t? For both I have t not equal to 0 because t is in the...

I know I just posted a topic, but I have another question. From my understanding, torque is force times the length of the lever arm, and the longer the lever arm or the more force there is, the more torque is applied. For moment of inertia, it is mass times the square of the distance from the...

How can I calculate the moment of inertia of a spinning top with charge Q submerged in an electromagnetic field? I've already calculated it for the case with no charge, but I don't know how to do this.

Hey, everyone, I have a question regarding quadcopters, when the set of the arms is of configuration X, to roll we increase the velocity of the two motors on the left/right and decrease the other motors on right/left, the question is when doing so the total angular velocity is zero that means...

Homework Statement Given a non magnetic rectangular plate with dimensions: L & B. The plate is of uniform density and thickness.There are 2 points equidistant from the center of the rectangular plate along the line at B/2. Both of these pivot points have 2 disks of radius R and mass M that are...

If electrons have a magnetic moment (or behave like they have) why don't all orient North Up in a magnetic field (pointing down)? Plus, if thought as magnetic dipoles, like poles repel, therefore all should point the same direction. In a Stern-Gerlach apparattus shouldn't the magnetic moment...

Hi everyone, i have a question Moment of inertia changes during rotation. Calculate the work done that changes kinetic energy? Angular moment (along the axis of rotation) L = I * w A point mass M rotates along an axis attached to a mass-negligible rod, of length r. If someone moves the mass M...

Hi everyone, i have a question Moment of inertia changes during rotation. Calculate the work that changes kinetic energy? Angular moment (along the axis of rotation) L = I * w A point mass M rotates along an axis attached to a mass-negligible rod, of length r. If someone moves the mass M at...

Hey, not sure if this is the right place to post this, but here it goes. how do you calculate the moment of inertia for a circle that is not at its center of gravity. I am trying to find the moment of inertia for a complex shape made of many circles, and this seems like a good place to start...

Homework Statement I will post a photo of the question in the thread once I've created it. I have found the magnitude and angle of the resultant force, but I am unsure of how to proceed. I find moments and couples confusing. Homework Equations $$\vec M = \vec r \times \vec F$$ The Attempt at...

If a rigid link pin joint-fixed on ground and is rotating freely about the same point with uniform ang. vel., can we say the vector form of angular vel. (omega) is nothing but moment of the tangential (perpendicular) vel. at the other end?

I just want to check to see if I am on the right path, I have to calculate the moment of inertia of a gearbox for an application. I was thinking of breaking down the input shaft/worm into different size cylinders since the shaft has different diameters for the the input and bearings. And then...

Homework Statement Attached. Homework Equations I=mr^2, I=(1/12)m*l^2 for a rod. The Attempt at a Solution Part A I got by doing I=(1/12)3.5*(2.6)^2+2*.7*1.3^2 (I added the moment of inertia of the rod and the balls). Part B since the axis is on one of the balls, I thought we don't include...

I have a blower within a system, and I'm trying to calculate the system inertia. I'd like to get the moment of inertia for this component as would be seen by the shaft. It's shape has me a little stumped (considered perpendicular axis theorem) on what method to use for finding the inertia. Any...