In mechanics, a couple is a system of forces with a resultant (a.k.a.net or sum) moment but no resultant force.A better term is force couple or pure moment. Its effect is to create rotation without translation, or more generally without any acceleration of the centre of mass. In rigid body mechanics, force couples are free vectors, meaning their effects on a body are independent of the point of application.
The resultant moment of a couple is called a torque. This is not to be confused with the term torque as it is used in physics, where it is merely a synonym of moment. Instead, torque is a special case of moment. Torque has special properties that moment does not have, in particular the property of being independent of reference point, as described below.
Here is the question, I am struggling with it as in all the past questions I have done it didnt matter if you worked out the work done by each force and then added it all together or if you added the forces together and then worked out the work done by the total force, but here the net force is...
In engineering statics I've learned the concept of bending moment, which in some way indicates an applied load that tends to bend the object, and it seems that it can move around freely in the reference frame. (I understand moment in engineering is not quite the same concept as torque in physics...
Hello I am just curious about something. In the image above, the spike shaped thing at #1, and the long thing at #2, what are those and what are their purposes? Since I don't know what they're called I can't google them lol. My current guess is that #2 is a mount for missiles, and #1 has...
According to Wikipedia, the definition of the Riemann Tensor can be taken as ##R^{\rho}_{\sigma \mu \nu} = dx^{\rho}[\nabla_{\mu},\nabla_{\nu}]\partial_{\sigma}##. Note that I dropped the Lie Bracket term and used the commutator since I'm looking at calculating this w.r.t. the basis. I...
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(Everyone here has been so helpful  thank you. Things I thought I knew, I now doubt; and this is so helpful to have this group.)
There is an current discussion on Yaw. I am enjoying that. And that raised an issue for me.
However, I do NOT want to hijack that thread, so I am posting...
Can I please ask for help with the following:
Forces proportional to the sides of a quadrilateral taken in order act respectively along those sides. Prove that the resultant of the system is a couple whose magnitude is represented by twice the area of the quadrilateral.
Not sure where to start...
So I have these 10k 5% resistors from Stackpole Electronics and just because I never actually took the time to look at a resistor datasheet beyond nominal resistance, tolerance, and power rating specs, I decided to look them up. Came across a couple things I wanted to ask about:
1) Maximum...
Hi, I was hoping to get some help on these five questions, I've been stuck on these and any help would be greatly appreciated!
1. Inflation rises and falls in a cyclical manner. If inflation is highest at 4.8% and lowest at 1.3%, what c for the equation y = a sin(k(x + d)) + c?
2. If the...
Hi,
I want to create a graph from the following data. The data is related to 3 different computers but the fields are same:
Please provide me the steps.
Garph1 BS
CPU Percentage 12
Memory Usage 15773696
sdiskusage total 9.82901E+11
sdiskusage used 1.41429E+11
sdisk usage free 7.91472E+11...
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Spin–spin coupling is encountered in the majority of NMR spectra. However, it does only occur when the two interacting nuclei are non"identical". But why is the coupling not occurring between "identical" nuclei?
I have been wondering about this because I could not think of a...
Hello,
A force couple is compose of two forces of equal magnitude, opposite direction and parallel lines of actions separated by a distance ##d##. The moment due to a force couple is called a pure moment because its value does not depend on the point about which the moment is computed. The...
Good morning sirs,
let's imagine a cylinder, surrounded on 360° by a coating of the same shape. I can close the 2 half using 2 bolt screws.
what's the maximun transmittable torque?
here's a scheme:
i would to consider the sum of forces as a normal force on the top of the cylinder, producing a...
Hello, there are a couple things about magnetism that I do not understand.
1. Why didn't we define the magnetic field to be in the directions of the force? This isn't really a technical question, I am just more curious about why it is this way. The way I was thinking of it, the math seems to...
I am reading Carroll’s Spacetime and Geometry, and I have seen the word “coupled” used multiple times in seemingly different ways. I have gotten the sense that it means some sort of interaction between particles, but Carroll refers to coupling between matter fields and the curvature of...
Does it take more electrical energy to transmit HF and lower frequencies than it takes to transmit VHF and above?
Are there any wavelengths beyond radio waves and gamma rays?
Is it true that the lower the frequency, the lower the amount of data that's being sent? I read on this wiki that...
Homework Statement
Find the following limit:
$$\lim_{x \rightarrow 10}\frac{x10}{4\sqrt{x+6}}$$
Homework EquationsThe Attempt at a Solution
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Please see attached work. I have a few questions (other than if my solution is correct or not).
First, is at step (ii)(C):
What makes me uneasy...
We repeatedly receive some fundamental questions, some of them of philosophical nature, which we're not very keen to answer  not because they weren't legitimate questions, but because we made the experience, that they simply lead nowhere, and, I'll have to admit, because of the lack of...
Homework Statement
Homework EquationsThe Attempt at a Solution
I am confused. It looks like the couple forces are at a angle pointing to the x axis.
So i did moment about a axis of that angle.
I found this angle/axis unit vector to be (0.6i 0.8j)
Then i found the moment couple about the x...
There are two polarization filters, A and B.
Polarization filter A has angle of 0° and B has an angle of 30°.
A photon is in superposition, so it doesn't have a definite polarization axis. The likelihood it's passing through a filter is depend on the difference between angle of the...
Hello,
I need to use the 0 and 1 digital pins while I have a motor shield on. I will include the link to the shield I plan to buy. Is it possible to solder a wire on top of the 1 and 0 pin (on the shield itself) while having no problems?
I circled the pins I am talking about in an ugly green...
Anyone else going through this process?
I thought I would be relieved once I submitted everything, but now I just feel worse!
I know I won't be hearing back from places until probably late February at the earliest, but having to just sit here and wait to hear back is brutal.
To those of you...
For the structure, find the distance from O (in direction OA) to the point where the resultant forcecouple system of the forces shown should have a resultant couple of zero. Give answer in metres.
a=90 N, b=289 N, c=549 N
Clockwise negative, anticlockwise positive.
Moment at a =...
I'm supposed to express the reultant force R of M, F1 and F2 in terms of F1, F2, r, s and α. But I need to know how to draw R first. How can one do this?
Does the couple create a force uppwards from O? Can I move F_1 and F_2 also to the origin and combine the forces?
Here is the image:
In a diode, we have N side, P side, and a depletion region, made of positive and negative charged sides. N side and P side of the diodes are neutral charge.
In N side there are free electrons. In the positive charged side of the depletion region, there are positively ionized atoms that "lack"...
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
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...
Hii...
I have to couple the noise into a communication cable for analyzing the performance of the communication. I am using a function generator which will generate a white noise of 12V(rms) and I have a current transformer to couple this to the communication line. The current transformer has...
While cleaning out an old house I found this book. I have later (much) copies of this book that I often refer to. A little mouse chewed but nonetheless a nifty find. Was amused there is a chapter on knob and tube wiring.


Homework Statement
Hello gentlemen!
I came across a real challeging problem about static, which states
the following: assume a force system is equivalent to a force \vec{F}_{1} and a couple M_{1}\vec{k} acting at a point \vec{r}_{1}. Find some point \vec{r}_{2} and a force \vec{F}_{2} so that...
I don't get it.
Imagine there is a stick leaning aganist a wall.
There is a moment couple somewhere on the stick.
The end of the stick hits the wall and the wall acts against it.
The sum of moment is 0 but since the moment couple forces cancel each other, the resultant force is the wall...
Homework Statement
This is the problem I'm having problems with.
Homework Equations
M=F x r
The Attempt at a Solution
Let me explain what I've been doing with the practice problems before it, because I fear I may have the wrong understanding.
For this exercise I just found the...
I hope this isn't too much for one thread, but I have a couple of questions regarding applied physics Ph.D programs.
1. Are there a lot of schools that offer degrees in applied physics, and what are some of them? I've found programs at places like Cornell, Stanford, Harvard, etc. but these are...
Homework Statement
A force couple acts on the frame, which is fixed at the base. Find the moment(s) and reaction(s) at the fixed locations.
Homework Equations
ΣMa = 0
ΣMb = 0
ΣFy = 0
ΣFx = 0
The Attempt at a Solution
Since it would be statically indeterminate, assumptions would be that the...
Two stars of equal mass M move with constant speed V in a circular orbital of radius R about their common center of mass .What is the net force on each star?the answer to this question was net force=GM^2/4R^2 .I want to ask that why net force not equal to zero although it is in translational...
Homework Statement
Attached is a pdf of the assignment problems, I'm looking at problem 1 under the "Try" section. It shows a rod attached to a wall bracket on the left, with a force applied on the right side.
I'm also including a link to the solution, it's under "Problem 3.83" ...
I am reading Gelfand's Trigonometry. In one of the questions he asks: "We know from geometry that a circle may be drawn through the three vertices of any triangle. Find the radius of such a circle if the sides of the triangle are 6,8, and 10."
My first question is, I know that if the diameter...
I found these [experimental data](https://en.wikipedia.org/wiki/Tests_of_relativistic_energy_and_momentum#Bertozzi_experiment) on mass increase.
> Data of the Bertozzi experiment show close agreement with special
> relativity. Kinetic energy of five electron runs: 0.5, 1, 1.5, 4.5, 15
> MeV (or...
Homework Statement
Calculate the magnitude and coordinate angles of the resultant couple moment, caused by the forces.
Homework Equations
M= r x F
The Attempt at a Solution
M3= 0.2* 80k= 16k
M2= 0.2* 120i= 24i
M1= 0.2*100j= 20j
M4= r x F= ?
I just can't seem to be able to expres r into a...
Homework Statement
two 50N are applied to the corner B and D , determine the moment of couple formed by the two forces by resolving each force into the horizontal and vertical component and adding the two resulting couples . Use the result to determine the perpendicular distance between the...
Homework Statement
According to Maxwells laws of electromagnetism:
If an electron spirals into the nucleus:
1. what would happen to the electron’s orbital frequency?
2. what would happen to the frequency of the emitted radiation? and
3. what kind of spectrum would be produced—a continuous or...
Hello,
I've been learning calculus and physics for the last year. Let's say i have 2 point masses mass one (m1) and mass two (m2). Their respective velocity vectors are constrained to one spatial dimension, with the directional component of their velocity vectors being determined by their...
Hello guys,
I have a small problem and I hope someone can help me.
I have a bit of information I want to "engrave" into this planet till our sun melts it down in 4,5b years. It's not important if someone finds it, wouldn't be possible anyway, but I want it to be 'somewhere' on or in this...
First question; I was measuring capacitance in various guitar pickup coils that have the same diameter of wire with an Extech LCR Meter, and it seemed to be that the more winds, the higher the inductance as expected, but I would get lower capacitance readings, too, both at 120 kHZ and 1k Hz...
Homework Statement
1.
It has been argued that power plants should make use of offpeak hours (such as late at night) to generate mechanical energy and store it until it is needed during peak load times, such as the middle of the day. One suggestion has been to store the energy in large...
Homework Statement
Hi! I'm not sure the title I gave properly reflects my problem, but I did not know how to describe it in another way:
(roughly translated from German)
"In three dimensions, we can divide the space in two parts through a plane. In four dimensions, that does not work anymore...
Homework Statement
470 Two couples act on the beam. If F=125 lb. determine the resultant couple moment.
Homework Equations
M=Fd
The Attempt at a Solution
I know CW is + and CCW is  ...and that is determined in the final answer,
I know the solution is taking Forces times the distance...
Homework Statement
In the figure 435 c , the bar is rotating at point b , but the book gave the taking moment at point b .. This is confusing... When we are taking moment at point b , the bar at particular point wouldn't move, am I right?
Homework EquationsThe Attempt at a Solution
Homework Statement
Homework Equations
I know that yin = 0.7mm, y2 = 0mm, the index of refraction for the sphere is 1.8 and the indices of refraction for the air surrounding it is 1.
The Attempt at a Solution
Not sure how to even begin with the given information. I was thinking I could...