Moment Definition and 1000 Threads

Hi can anybody tell me if my working for finding the moment of a b c is correct? Taking clockwise as +ve Ma+1.2k x 3 +0.7 x 7 = 0 Ma= -8.5Knm Mb-8.5+1.9k x 3=0 Mb=2.8kNm Mc=1.2k x 4 +1.9k x 7 -8.5k=0 Mc=-117.85Nm Hence Point B has the biggest moment am I right? However the...

In "An Introduction to Electrodynamics", Griffiths gives the following equation for the dipole moment: p=\int r' \rho(r') d\tau'. My question is, in general, what volume am I integrating over? It seems a bit arbitrary to me. I assume I'm integrating over whatever volume is enclosing the charge...

Homework Statement Find F, the force acting at the top of the gate. The gate is 2m high and 2m into the page. It is hinged at the bottom (red dot in the diagram) Density of fluid varies linearly. 1000 kg/m3 at the top and 1600 kg/m3 at the bottom (depth of 4m) Homework Equations...

Homework Statement A force of 56 pounds acts on the pipe wrench shown. find the magnitude of the moment about O by evaluating || OA x F || Homework Equations || OA x F || The Attempt at a Solution First I tried to find my vector component for Force which I got -56 [ cos(30)i +...

I need to find the moment of inertia of a sphere of radius ##r## and mass ##m## about an axis through it's centre. I've already done it and got the correct answer of ##\frac{2}{3}mr^2## however I have tried doing it using a different method to see if I get the same answer, but I don't, and I...

Homework Statement I have attached a diagram Homework Equations 14 + Va -32 + Vb -15=0?? or Vb=-15? The Attempt at a Solution The reason why I cannot attempt this problem is that I'm not sure whether it is valid that there can be a point load at Support B or whether they are...

hi everyone, help me, To calculate the mass moment of inertia at output shaft with respect to input shaft in the two stage planetary gearbox. Torque at input = 15 Nm input speed = 1440rpm stage I zs=14 zp=23 zR=61 fixed stage II zs=21 zp=40 zR=102 fixed

I read that for a rotating body the kinetic energy ##E_k = \sum \frac{1}{2}mv^2 = \frac{1}{2}{\omega}^2∑mr^2 = \frac{1}{2}I{\omega}^2## where ##I## is the moment of inertia. If we did the same thing for momentum then ##P = ∑mv = \omega\sum mr## So why is angular momentum ##I\omega=\omega\sum...

In classical mechanics you want to calculate the moment of inertia for hollow & solid: lines, triangles, squares/rectangles, polygons, planes, pyramids, cubes/parallelepiped's, circles, ellipses, parabola's, hyperbola's, sphere's, ellipsoid's, paraboloid's, hyperboloid's, cones & cylinder's...

Homework Statement A 10 m long steel beam which weighs 700 kg lies on a roof. The beam sticks out 4,5 m over the edge of the roof. How far can a person weighing 80 kg go out on the beam (on the part sticking out over the edge of the roof) without the beam tipping over? The answer is...

Homework Statement A cantilever beam (prismatic, rectangular cross section) is loaded at the tip by a force P and at half its length L by a moment M. a. Calculate the reaction force and moment. b. Draw the shear force and bending moment diagrams Homework Equations ∑F=0; ∑M=0 The...

Couple moment problems -- Calculate the distance? Homework Statement http://imageshack.com/a/img691/1734/804i.jpg Homework Equations M = F x d The Attempt at a Solution M = Fxd 20Nm = 35N*x x = 0.57m cos 30 deg = x/d d = x/cos 30 deg = 0.57m/cos 30 deg = 0.66m...

Homework Statement Recently I am undergoing such experiment in school and my lecturer asked that, as if any changes in the distance(vertically) will there be changes in the force/reading of it?Assuming there is no changes in anything else except the position of the tools. (Since the "Cell...

Homework Statement Calculate the moment of inertia of a cube which rotates along an axis along its diagonal. Homework Equations Moment of inertia definition: I = \int \rho (\vec{r}) \vec{r} ^2 dV Angular velocity vector; \vec{\omega}=\omega (\frac{1}{\sqrt{3}}, \frac{1}{\sqrt{3}}...

Homework Statement For the overhanging beam in the figure, A) draw the moment diagram indicating all critical values including the maximum moment (Value and location), and B) write the moment function, M(x), for B-C section in terms of x coordinate as shown in the figure. Homework...

(Figure is attached) Find the tension in the cable AB such that the net moment about the hinge axis CD induced by the forces F and P is zero. The force F is applied at point A and the force P is applied at point E. The magnitude of the force P is P = 65 lb. Two coordinate direction angles for...

If I can to calculate the 1st and 2st moment of inertia of areas and volumes, I can compute for curves and surfaces too?

Homework Statement Find the moment of inertia of a hollow sphere about a vertical axis through its center in terms of its mass M and radius R. Homework Equations I=\int r^{2} dm The Attempt at a Solution I've been curious about different methods for finding moments of inertia...

Hi, So recently I read about the massive 3 gorges dam changing the mass moment of inertia of the Earth to such an extent that the days will now be 60ns longer. Then I thought, how will this effect the orbit of the Earth about the Sun? Any thoughts?

Answer check please -- Moment of Inertia Calculations For question 1 I got T=mnut * r pulley * gravity For question 2 I got Isystem = 1/2 M(R23 + R24 + m (R21 + R22) First day of physics lab and I just wanted to double check that these are correct. Thanks.

Homework Statement A thin disk is 100g. It's diameter is 20cm. It's thickness is 2cm. Rotation is about the central axis (ie. perpendicular to the symmetrical plane). Answer in kg*m2 Homework Equations I=(1/2)MR2 M is the mass R is the radius I is the moment of inertia The...

Homework Statement For the beam shown in the figure: a) Draw necessary free body diagrams b) Calculate support reactions c) Draw the shear force and bending moments Homework Equations ∑Fy = 0; ∑M = 0; V(x) = ∫ L(x) ; M(x) = ∫ V(x) The Attempt at a...

I just wondered how I transform electromagnetic dipole moments. For example assuming I have magnetic dipole moment μ in a frame without E dipole moment. Then I boost orthogonal to μ. Now I would like to determine the electric dipole moment. I could use the magnetic potential and transform...

Homework Statement For nickel, which has an atomic magnetic moment of 0.61 and an atomic weight of 58.7, calculate the magnetic moment per kilogram of the material Homework Equations None given The Attempt at a Solution Do I not need density to use formula for saturation...

Hi, Can anyone give a derivation of the quadrupole moment in the TT gauge ( Equation metioned below ) of the gravitational wave ? QijTT(x) = ∫ρ(xixj-1/3δijr2)d3x Where ρ is the matter density Thanks In Advance

Homework Statement Draw the shear and moment diagram for the beam Homework Equations ∑Fy=0 ∑M=0; ΔV=∫w(x)dx ΔM=∫V dx The Attempt at a Solution I am firstly finding the external forces as any statics problem(Ay=13.5kN upwards, By=13.5kN upwards).Then I found the equations of the...

Homework Statement This is the question that I am struggling with. http://postimg.org/image/5kb0pur3z/ I need to plot shear force and bending moment diagram of it.Homework Equations The beam is in static equilibrium so algebraic sum of forces in x and y direction equal zero. Also, moment is...

I am computing the \hat{I} - moment of inertia tensor - of a cylinder with height 2h and radius R, about its axis of symmetry at the point of its centre of mass. I am working in cartesian coordinaes and am not sure where I am going wrong. (I can see the cylindirical coordiates would be the...

Hi, Consider a 2D laminar only rotating about the z axis, with the axis origin at the bottom left hand corner and adjacent sides coinciding with the z and x axes. so ω = (0,0,ωz) y = 0 I don't understand how the IXZ component is 0 to just leave the IZZ component?

Hello I just joined this forum and this is my first thread here. This is my assignment question. I'm supposed to find elastic positive bending capacities around the horizontal axes for the following cross section shown in pic. The elastic stress in tension is 10 ksi and in compression is 15...

Homework Statement A homogeneous catenary ##z=acosh(x/a)##, ##y=0## and ##x\in \left [ -a,a \right ]## is given. Calculate the center of mass and moment of inertia Homework Equations The Attempt at a Solution I started with ##x=at##, for##t\in \left [ -1,1 \right ]##, therefore...

I once called my old high school physics tutor by phone. He was not that fluent in English. He needs to be appreciated by me because without him, mechanics would have been much difficult... Our conversation began and we spoke about some concepts, how life went on and so on...He was talking...

Ok, so the system consists of two massive spheres, m1 and m2, of radii a and b respectively, connected by a massless rod of length R, as seen in the diagram attached. The question is to calculate the moment of inertia tensor. Sol: Set the origin at the centre of mass . So that we are in...

Homework Statement Homework Equations The Attempt at a Solution With this problem and in general, I am having difficulties knowing what should be the cubic and what shouldn't be from visual inspection, so in this case I can't tell why I_x is 1/12ba^3, as opposed to 1/12ab^3. How can I tell...

Homework Statement An homogeneous cube of mass M and side 2a spins around one diagonal of the faces with constant angular velocity w. Show that the size of the angular moment in relation to one of the fixed vertexes is \sqrt{\frac{43}{3}}Ma^2w What I visualize here is a cube with one of its...

The calculation for the maximum bending moment is to be verified experimentally using a strain gauge bonded to the outer surface of the beam, at the point where the maximum bending moment occurs. Derive an equation which could be used to calculate the bending moment from the measured strain...

Homework Statement Hollow circular beam with outside diameter 350mm, and wall thickness of 60mm E=60 Gpa beam length 2m Force applied to beam at midpoint of beam (1m from each end) F=200KN Force applie from the Top down, Ra , and rb from bottom up Homework Equations...

Ok me and my friend have clashed with solutions to calculate the moment of inertia of a flywheel and I think I have it after a while but I'm not so sure about my maths! The solution he ended up with was a lot larger and more complex :) really enjoying this forum:)

Homework Statement A hydrogen atom in its ground state actually has two possible, closely spaced energy levels because the electron is in the magnetic field B of the proton (the nucleus). Accordingly, an energy is associated with the orientation of the electron's magnetic moment (μ)...

Homework Statement How could I calculate the piecewise formula for M(x)? Homework Equations The Attempt at a Solution From constructing a free body diagram it looks like up until the pin support, M(x) = -Fy*x (Fy being the force pointing upwards at the wall) but I am confused...

Homework Statement There is the moment of inertia about an x and a y-axis named, I_{x}, I_{y}. Then there is the moment of inertia about the centroidal x and y-axis named, \overline{I}_{x}, \overline{I}_{y}. Often we can look up these values in a table (like the figure included) and apply...

With mean = 2 with exponential distribution Calculate E(200 + 5Y^2 + 4Y^3) = 432 E(200) = 200 E(5Y^2) = 5E(Y^2) = 5(8) = 40 E(4Y^3) = 4E(Y^3) = 4(48) = 192 E(Y^2) = V(Y) + [E(Y)]^2 = 2^2+2^2= 8 E(Y^3) = m_Y^3(0) = 48(1-2(0))^{-4} = 48 is this right?

Homework Statement In the question (see attached images), it asks me to draw the shear and moment diagrams for the beam shown in the figure. To do this, we use the equilibrium equations. What I do not understand is why M is present in the equilibrium equation for bending. Isn't the pivot...

Homework Statement I'm supposed to solve for the maximum moment assuming the beam bends about the y-axis (not the z axis as shown in the image. Same image for different questions). I don't understand how to find the moment of inertia in this case. The solution gives the moment of inertia for...

Hi I'm new to this forum so still getting used to it! I have to find the moment of inertia of a circular flywheel which has radius, a and mass m! But also had area density (mass per unit area) of ρ0, Where ρ0=ρa(1+r/a) I know moment of inertia is the integral of a^2 dm and in order to...

Homework Statement Calculate the magnetic moment of the ground state of \,_{20}^{39}Ca. Compare to the experimental value in table 1. Homework Equations Nuclear Shell Model knowledge The Attempt at a Solution Well firstly the magnetic moment of the nucleus similar to the spin is...

Homework Statement Calculate the moment of inertia of a uniform, solid cylinder about it's perpendicular axes. The cylinder has length L, radius R, and total mass M. It is centered on the origin with the z-axis running through the center of it's circular faces. Homework Equations I =...

The problem I am currently trying to right a lab report on a experiment trying to find a flywheels moment of inertia. In the lab we had a fly wheel connected to a mass on a string, and measured the position of a point on the wheel as the mass was accelerating downwards. The data was analysed...

I am given that The kth moment of an exponential random variable with mean mu is E[Y^k] = k!*mu^k for nonnegative integer k. I found m^2 (0) = (-a)(-a-1)(-beta)^2. The answer I found is however mu^2+a*beta^2 which is different from the k! From the given formula. Could someone help me figure it...

Homework Statement http://s1345.photobucket.com/user/Duk_Bato/media/Untitled2_zps52bc2429.png.html Homework Equations M= F * d The Attempt at a Solution I can't solve the last part the iii) My problem is roller only got one force and how to resolve it? It may sound excuses but, it will...