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

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from control torque to magnetic moment

I am designing a system which generates a magnetic field to make itself move in space (a cubesat with magnetorquers). This magnetic field is known as the magnetic control torque, i.e. it will torque ...
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48 views

Total angular momentum of a continuous body

I find the definition of total angular momentum $\mathbf{L}$ of a system of $n$ material points with respect to a given point $Q$ as the sum of the momenta $\ell_i=\mathbf{r}_i\times\mathbf{p}_i$ ...
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17 views

Choosing a term's sign — a rolling body question

https://prettygoodphysics.wikispaces.com/file/view/Rollin_and_Slippin.pdf In this link's first problem, top-spin is applied to a ball that slips; while the ball moves forward, it spins clockwise. ...
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1answer
28 views

Angular acceleration of two rods joined in the center - did I do this right?

The question is: The moment of inertia of a thin rod of length $l$ and mass $M$ about a perpendicular axis through its center is $\frac{1}{12}Mt^2$. The object shown consists of two ...
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30 views

Unilateral Torque Constraint on the foot-ground interface

I was studying the basics of legged locomotion and came across the unilateral force and torque constraints at the foot-ground interface. I understood the implication of the unilateral constraint on ...
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30 views

Applying a Force on a non fix body [duplicate]

If we apply a force on a fixed body and if that body rotates, we calculate torque about that pivot point. But if that body is not fixed and then we apply force that provides translational motion and ...
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1answer
62 views

Boomerang angular momentum

So I'm building a boomerang to fly 200 feet in order to do that I was told to increase the moment of inertia to increase the resistance from change in state, and I was told that it would increase the ...
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156 views

Coefficients of Friction in Equilibrium Ladder Problems

A problem asked me to find the the minimum angle the ladder system could have while still remaining in equilibrium: If you want to examine my reasoning: Let's take the lower end of the ladder to ...
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1answer
79 views

How does the net torque have to be 0 at all points for static equilibrium? [duplicate]

I know that for a mass to be in static equilibrium two things have to be satisfied: $\sum F=0$ and $\sum T=0$, where $T$ represents torque. However, I am not sure how the latter can apply in a ...
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2answers
111 views

Clearing up confusion about calculating torque

Suppose you have a shape consisting of two perpendicular rods (the whole shape is a rigid body) which stands upright so the plane of the rods is perpendicular to the plane of the ground, and the ...
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19 views

Overall Velocity of Body with Multiple Wheels

Let's say you have some object, a car or whatever, that has multiple wheels going in multiple directions, each of which can spin at different speeds. How would one go about getting the overall ...
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221 views

Ladder equilibrium problem - Where do the hinge forces go?

In my physics homework there is a problem about a hinged ladder like this and a man is standing on one of its halves. The two parts of the ladder are hinged together at the top. My question is, ...
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29 views

Force and Torque being applied off-center due to magnetic forces [duplicate]

Say that I have two magnetic dipoles, one of which is rigidly attached to a freely movable inflexible body at some point that is not at the body's center of mass, while the other is fixed in space. ...
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41 views

Is it possible to reverse gravital direction of center of a mass by gyroscopic movements?

I am sorry that I don't know exact terms to define my question in physics. I watched a few videos that showed moving objects by its own like cubli (gyroscopic moving parts by means of mini motors and ...
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0answers
184 views

Torque, angular velocity, keeping track of the rotation of a sphere

I'm trying to simulate a rotating sphere due to a torque on a specific point on the sphere. Say the sphere is connected to a string (so variable length) on the bottom, on $(r, \theta, ...
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1answer
80 views

Forces Create Angular Acceleration And “Straight” Acceleration - But How Much Of Each?

Let me set up the following problem for a rectangle floating in space: We know its dimensions. We know its mass. There's a force pushing it for a known amount of time - we know the angle & ...
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1answer
79 views

How does ground interact with a box rotating around its corner?

I have some questions about how forces $F$, friction force $F_{friction}$, and normal $N$ interact in order to the box below to turn (clockwise) about the red corner, without sliding. The force $F$ is ...
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1answer
61 views

Would equations for a spinning top be an (x,y,z) vector [duplicate]

I am following the equations on this page, and for torque it is $mgr\sin\theta$, but I am curious about $r$. I am working on a game and I want to correctly model the top, and am curious if $r$ should ...
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1answer
677 views

Calculating Resultant Force and Torque

I'm working on a sandbox game that allows the player to build a spacecraft and attach thrusters in arbitrary locations on the hull of the spacecraft. The game is set completely in 2D. (I'm a ...
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0answers
37 views

Why do we consider the application of force as well as bending moment in finding the moments of a beam?

In the standard techniques of beam related problems, solving for moment at any cross section includes counting the torque due to shear force as well as some extra moment, which according to me ...
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1answer
238 views

Transfer of angular momentum during oblique impact with(out) adhesion

I am solving a problem of 2 identical spherical particles colliding. The impact is oblique. I consider both normal and tangential contact forces. Tangential force is a combination of elastic force ...
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1answer
146 views

How is Magnetic force on a current carrying conductor $Blb$

I was reading an answer about torque acting on a rectangular current carrying loop kept in a uniform magnitude field B. Force acting on each sides is $F_1$, $F_2$, $F_3$, $F_4$. It's written here : ...
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61 views

What is the linear and rotational motions generated by a force not on the CG?

Given a force that is applied to a free body, not directly towards, or away from the centre of gravity, how would you calculate the amount of linear and rotational velocities generated, as the farther ...
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1answer
109 views

What is the intuition behind the direction of torque? [duplicate]

I've seen the other posts on this question, but unfortunately I'm still having difficulty understanding the meaning of the direction of the torque vector. It makes intuitive sense that the magnitude ...
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31 views

Wikipedia's derivation of torque related to angular acceleration [duplicate]

Wikipedia derivation of the relationship between a torque and an angular acceleration is given here. Could someone help me to see how the following: $$\vec{\tau} = \left(-\sum^n_{i=1}m_i [\Delta ...
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19 views

Is it possible to impart a moment with soundwaves?

How can one adjust the properties of a sound wave to use it to spin an arbitrary object of shape S in a medium comprised of the same material. My intuition tells me that it would be much more ...
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1answer
122 views

Coordinate System vs. Angular Properties vs. Centroid

Please help me check my understanding related to the rotational motion of a 3D rigid body after reading some Physics textbooks and googling for some more materials (e.g., Wikipedia's Torque, ...
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1answer
55 views

Thrust to Weight ratio in Space with an off set CoM

With regards to this thread, Thrust center in space My question is, if the thrust to weight ratio was increased so that it was much higher than the weighted mass of the sphere (ship), would the ...
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46 views

Rolling resistance

Today, my physics teacher asked the following question (and gave it as homework): How can a moving body deaccelerate both in means of center of mass and rotationally? I quickly answered that ...
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1answer
178 views

Moment around a point in a frame

Note: Both diagrams are 2d(they might look 3d because I drew them manually.) I have a prismatic frame that looks like this: I made a section on the half of the first pillar(the red line represents the ...
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120 views

Correct way to calculate torque produced by axle

For my electrical engineering course, we had to build a simple DC motor that can lift a coin. I have tested the motor, and here are the results: rotational speed (no load): 3630 RPM (380 rad/sec) ...
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206 views

Torque of Air Resistance on Ellipsoid

Imagine an non-rotating arbitrary free, rigid ellipsoid with in some arbitrary direction with velocity $\vec v$. Assume linear drag ($\vec F=KA\vec v$ for some constant K, where A is the cross section ...
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1answer
1k views

Force acting on a simple rigid body in space

so this is the question that's been bothering me: Say you have a simple rigid body in space that is at rest or travelling with only translational motion at a constant speed. Say that the body is ...
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262 views

What happens if torque = 0?

I am trying to understand torque on a current loop which is placed in a uniform $\vec{B}$-field. (http://i.stack.imgur.com/oNO8a.jpg) It says that $\vec{F}_2$ and $\vec{F}_4$ have the same ...
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167 views

Calculating rotor torque out of mass center

Suppose I have an engine with propeller. I know there is aerodynamic force pushing the propeller opposite direction the engine is turning it. One component of this force is creating lift, but second ...
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1answer
621 views

Calculating torque with gears and wheel-axles

For my homework in engineering, I was given a question like this: There is an axle attached to a gear, which is meshed with another gear, which has an axle attached to it. I am given the diameter of ...
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0answers
322 views

Dose the gravitational force produces precession in the spinning top?

I'm new at classical mechanics but the text book says there is the torque in the spinning top which generated only by gravitation. It is hard to explain the situation, I've add the link. ...
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1answer
87 views

Pendulum system: how is derived the output as Energy?

Good day to everyone, I want to understand in which way the "Energy equation" is been implemented to this pendulum system. $x_1(t)$: The angular position of the mass $x_2(t)$: The angular velocity ...
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1answer
420 views

How can the torque a bicycle experiences be calculated based on the center of gravity, weight and a force?

The position center of gravity of a bicycle and its rider is known, and the distance from it to the point of contact of the front wheel with the ground, in terms of horizontal and vertical distance (x ...
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2answers
540 views

Finding work done by rotational force?

A disk with a rotational inertia of 5.0 kg·m2 and a radius of 0.25 m rotates on a fixed axis perpendicular to the disk and through its center. A force of 2.0 N is applied tangentially to the ...
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3answers
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How much torque does it take to turn a doorknob? [closed]

How much torque does it take to turn a doorknob? I'm not looking for an exact answer, just a ballpark for someone who doesn't have a sense of everyday amounts of torque. Here's a very ordinary ...
-1
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1answer
576 views

Finding the mass of bed/Patient [closed]

One of my friends has a problem and we don't know how to get this done, We want to to know the mass of a patient who is laying on a bed. One scales was put under the foot of a bed and weighed 232kg ...
-1
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2answers
84 views

Torque for rotation

The force for revolution of earth is provided by the gravitational force of attraction between earth and the sun. What provides the force(torque) for the rotation of earth?
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1answer
91 views

does the current's direction on a loop with a magnetic field affect the torque?

I have a question in my book The question is very easy, but then my solutions manual gave me unexpected answers I don't get how in d) they conclude the vectors go in the opposite direction, but ...
-1
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1answer
1k views

Calculation of torque for motor used in 4 wheel robot [duplicate]

Possible Duplicate: Torque Required For a Motor to Move an Object on Wheels? I want to build a 4 wheel robot. the maximum weight of the robot is approximately 100 kg. and the radius of my ...
-1
votes
2answers
96 views

Torque at a disc sandwiched between two rotating discs

I have a question in my mind regarding torque transfer taking place in the current situation. There are three rotation elements A, B & C as shown in the figure. The rotating element A is ...
-1
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1answer
351 views

How do I know which force to use in moments calculation?

I'm working on some Statics problem, with the method of joints, etc and for all of them, we use sum of moments = 0. However, I'm very confused about which forces I should use to find the sum of ...
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1answer
533 views

Proof for torque=force*perpendicular distance to line of action of force [closed]

I want to derive from first principles the proof for magnitude of torque about a point O = perpendicular distance from O to the line of action of the force * magnitude of the force. I want to derive ...
-4
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0answers
103 views

maths question on levers [closed]

Someone holds a 2kg weight in their hand at a distance of 35cm from the elbow (fulcrum) and the downward force (load) due to the weight is 20 Newtons. Calculate the effort in Newtons that the ...