The tendency of a force to rotate an object about an arbitrary axis.

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Potential Energy for dipole in Electric Field

Potential Energy is the work done by the external agent in turning the angle of the dipole from the U=0 position to another position against the influence of the electric field applied right? So if ...
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20 views

Moment Of Inertia, Angular Acceleration [closed]

Consider a pulley and and a string is attached to the pulley with a mass hanging and then dropped. Explain why the acceleration is greater when you attach a string to a larger radius of a cylinder. ...
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3answers
38 views

How is rotational torque calculated when a force is applied uniformly over a surface?

Currently, the formula I am using to calculate the rotational torque applied onto an axis is $T = Fr\sin \theta$, where $T$ is the torque (in $\mathrm{N\ m}$), $F$ is the force acting, $r$ is the ...
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2answers
26 views

DC motor acceleration

I'm doing a research project on the mathematics of robotics. For this research project I need to use calculus somewhere in the project. My plan was to calculate the acceleration of the robot and find ...
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0answers
38 views

Centre of gravity of system [closed]

We have a uniform rectangular tray of dimensions 40x60, with weight 3. We place the coordinate axes in such a way that the bottom-left corner of tray is at the origin and the tray sides are parallel ...
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2answers
69 views

Shelf always tipping over when pushed, thanks to normal force

A while ago, I encountered a problem with a person pushing a shelf at the top, with the center of mass located in the middle. The task is to find the maximum magnitude of the force vector, not causing ...
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27 views

Adding multiple torque vectors together to determine resultant torque

I am working in a 2D environment, where there are multiple angular forces (torque) applied at an object. The way I calculated 1 torque "application", was by: ...
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25 views

Torque of a current loop (circular) inside another one

I have a circular coil of 12cm of radius that conducts a current of $13A$. A second coil, with 50 turns, and a current of $1.3A$ is in the certer of the other one. I need to find: a) the magnetic ...
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3answers
49 views

What does the “moment” in the moment of force or the moment of inertia refer to? [duplicate]

According to the Merriam Webster dictionary: Moment - a very short period of time Does the word "moment" in quantities like the moment of force or moment of inertia refer to this colloquial ...
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3answers
33 views

Perpendicular Distance for Moments

My question is: Is perpendicular distance in the equation $\tau=Fd$ the distance of the yellow or red line? My belief was that it was the red line, however when I take moments about $O$ I get ...
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3answers
40 views

Why does a pot start rotating when coffee is stirred inside?

I usually make Turkish coffee as my morning coffee. I have a small somewhat rounded pot with handle on one side. I noticed that when I pour water in and start stirring, pot has a tendency to start ...
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12 views

How to Calculate Engine Torque from Drive Torque @ The Wheels for All wheel drive and Front wheel drive? [duplicate]

Would it be possible for someone to explain how engine torque is calculated from drive torque at the wheels and how this differs between AWD and FWD. Thanks.
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145 views

Rotational Torque Versus Thrust on a Screw

We all used screws and tightening them before, but here is my question. If a Thrust-like load behind the other side of the screw can move the screw out (example pushing), then how much force is it ...
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1answer
83 views

How to calculate torque required? [closed]

Here's my problem diagram: I am working on a hobby project in which a motor is required to rotate a pulley that is connected to a pendulum as shown in the image. The maximum torque, Horsepower and ...
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1answer
54 views

What is the speed of the skaters in this case? [closed]

You're choreographing your school's annual ice show. You call for eight 60kg skaters to join hands and skate side by side in a line extending 12m. The skater at one end is to stop abruptly, so the ...
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1answer
300 views

What is the meaning of “moment”?

What is the meaning of moment? I'm little confused about the word as there are some terms like moment of momentum, moment of mass, moment of force, etc. I want to know what exactly is meant by the ...
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1answer
22 views

where does deformation take place in a shaft subjected to a torsion?

If we rotate a shaft about an axis it is said to be under torsion. It is also said that there will be a deformation. What I'd like to know is will the shaft actually WARP during the process? If not ...
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24 views

flow rate measurement of a fluid

I had an experiment related to piping networks in my institute. In the experiment there was a device that was measuring flow rate based on rotations of a fan-like system. This created a doubt in my ...
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2answers
40 views

Why moment equilibrium must be calculated around the center in this problem?

Consider this problem, which ask for the value of the two normal forces (friction is negligible). Easy, right? You calculate the moments around G, the center of mass, and equate them to 0 (the ...
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1answer
20 views

Calculation of support reaction in rigid body rotation and collisions

I can't understand the logic behind the calculation of torques exerted by supports in rigid body motion, especially rotation. The equation of angular momentum is ...
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2answers
39 views

Disk let free to rotate

A rigid body moving with no constraints, in particular rotating, will rotate necessarily about a principal axis of inertia. I thought that the reason of this is that otherwise, the angular momentum ...
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1answer
38 views

How does distance affect force?

In the image below, the system is in equilibrium. Some force is applied at the bottom of the vertical pole and is being opposed by some force at the top by the horizontal pole... But I feel as though ...
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1answer
19 views

Finding the force exerted by a mass at different contact points

Okay so I've been doing a math assignment on torque which has to have real-world applications so I've gone off on a massive tangent trying to incorporate physics principles and trying to get them as ...
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2answers
34 views

Torque and a pulley

I'm supposed to find, symbolically, what the moment of inertia of the pulley is using $T_1, T_2, r,$ and $a$. Obviously the base equation would be the sum of the torques equals $Iα$. I have the ...
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1answer
36 views

Equilibrium of a Solid Body

To find the torques around B, see the figure below, I took the cross product as followed: and we know that $W=160 N$ but when I insert that value into the the equation in the red box, I get ...
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17 views

Angular acceleration of rigid body due to a torque

For the rotation of a rigid body about a fixed axis $z$ the following holds. $$ \vec{τ_z}= \frac{d \vec{L_z}} {dt} =I_z \vec{α} \tag{1}$$ Where $ \vec{τ_z}$ is the component parallel to the axis ...
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23 views

Motion of current carrying rectangular coil in magnetic field

a current carrying rectangular coil is placed in a uniform magnetic field as the plane of coil is parallel to the field at the beginning . assume that there is no restoring torque and no friction. i ...
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3answers
42 views

Interaction between magnetic moments and magnetic field

Consider a particle with a magnetic moment $\vec{m}$. For simplicity, suppose that this particle is a circle in the plane $xy$ which can rotate around its center of mass along the $z$ axis. If this ...
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1answer
31 views

how the form factor (stress - torque) is derived?

I am working on an experiment of rheology and I need to calculate shear stress in order to calculate the viscosity. After some research I found that for the type of viscometer I will be using ...
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2answers
103 views

Angular equilibrium on a see-saw

I have a tonne of questions related to see-saw equilibrium because most places I've been to online only deal with horizontal equilibrium - but static equilibrium can occur on an angle too. My ...
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20 views

Torque required to rotate a drum in horizontal position with loose load

I am constructing a low heat drum dryer for fermented cocoa beans and am using a HDPE plastic drum of dimensions 610 mm diameter, 910 mm length and 200 litres volume. Thickness of the wall of the drum ...
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0answers
20 views

How is equilibrium achieved when masses are unbalanced?

Consider the see-saw scenario shown below (This image was from a Phet simulation) If you place a 5kg mass 0.25m from the pivot point, the seesaw will have net torque in an anticlockwise direction, ...
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1answer
42 views

Force and Torque

Think of a uniform sphere. Sometimes if a force is applied to the sphere it does not only move but also spins. So there is a torque. But is it possible to calculate which part of the applied force is ...
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1answer
33 views

Component of angular momentum perpendicular to the rotation axis in rigid body rotation

I have difficulties in understanding, in the rotation of a rigid body, the properties of the component of the angular momentum vector $ \vec {L} $ which is perpendicular to the fixed axis of rotation ...
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4answers
93 views

Is torque necessary in rigid body mechanics? [duplicate]

Suppose we have a weightless, rigid rod fixed at one end, but free to swing at the other, where there is a mass $m$ attached. If we want to determine the tangential acceleration of the mass using ...
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21 views

Force by torque or force by speed with make the body jump?

I have a small object made of plastic weighing 3kg and I want to make it jump with the help of a dc motor and a plastic rod attached to it (4 such motor with rod are attached on the object at 4 ...
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1answer
42 views

Why will kinetic energy decrease?

Specific situation : A ring of mass M and radius R is rotating about its axis with angular velocity w. Two identical bodies each of mass m are now gently attached at the two ends of a diameter of the ...
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35 views

Torque on rotating rigid body and pivot point [duplicate]

Consider a rigid body performing a rotational motion around a vertical fixed axis $z$ with constant angular velocity $\vec{\Omega}$. The angular momentum vector $\vec{L}$ is not parallel to $z$ (and ...
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2answers
104 views

Forces that exert torque on a rigid body in rotation when angular momentum is not parallel to angular velocity

I'm confused about the rotation of a rigid body, when the angular momentum $\vec{L}$ is not parallel to the angular velocity $\vec{\omega}$. Consider a barbell with two equal masses that rotates ...
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1answer
41 views

Calculating Torque

So I am building a wheeled project, and need to find out the torque and power I require from my motors. The total project weight is about 40kg. I looked online, and found the following formula for ...
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2answers
66 views

Rotational work and forces such as static friction or ropes tension

I'm confused about the rotational work, defined as $W=\int_{\theta_1}^{\theta_2} \tau_z d \theta $ Where $\tau_z$ is the component of the torque parallel to the axis of rotation $z$. Consider a ...
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1answer
84 views

Calculating force with two fulcrums and many forces [closed]

I may not be wording the question the right way. I have a lever. About 2/3 the way back there is a pivot point. We'll call this B On the very front (end of the lever) there is a block that the lever ...
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2answers
45 views

Why is Torque Generated from Friction?

Why does a rolling ball get torque from friction. I understand torque in relation to lever arms and the force being perpendicular to said arm. But what about wheels? There is no lever arm so how is ...
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2answers
105 views

Can torque relations actually be *derived* from Newton's Laws, or is it something extra?

For a long time I have wondered if there is a way to show that the rotational analogs of Newton's Laws are a direct consequence of just those laws, or are we adding more to them? I understand ...
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1answer
76 views

Why does a force parallel to the axis of rotation do not produce torque? [closed]

One explanation can be that Torque is a cross-product (r x F). I want to know what is its physical interpretation.
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3answers
420 views

Do supports exert torque?

I think I'm missing something about torques. Do supports exert torques? Consider these two situations I'm confused about. A rod is attached in to a wall so that it cannot rotate. Since weight ...
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1answer
28 views

What kind of motion is caused by nonzero torques about two parallel axes?

Say on a rigid body there are non-zero torques about two parallel axes. About which axis does it acquire a angular acceleration? I'm looking for a mathematical explanation.
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1answer
57 views

Torque and Force of Pulley fixed on side

If you had only 1 pulley that is connected to a rotating shaft, and which has a rope circled around it once, with a mass M on one side and with the rope fixed on the other end, how would you then ...
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52 views

Rotating rigid rod in empty space [duplicate]

To begin, we assume there is a rigid rod in empty space which has no rotation with respect to the fixed stars. The frame of the rod is now an inertial reference frame, say $F$. 1) The rod now has a ...
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4answers
189 views

Why does Torque exist?

Specifically, why does force increase with the moment arm? What about making a perpendicular force farther away from the axis of rotation increases it? How does the moment arm cause that?