Questions tagged [torque]
This tag is for questions regarding to torque, which is a measure of the increase in angular momentum over time.
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I am facing trouble understanding the concept of torque about an axis [closed]
The torque about a point has a clear definition, $\vec{r} \times \vec{f}$, and I read somewhere that the torque with respect to an axis is the same for any point on the axis, but I don't understand ...
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Is torque due to gravity about the center of mass zero?
I know torque due to Fg is zero on a level rod. However if the rod is tilted like below, is the torque still zero? The pivot point is on the center of mass.
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Can joint stiffness be controlled by actuators?
I am a software developer running this simulation and have some trouble understanding the underlying physical problem. My description of the problem is therefore probably not perfect, but I hope ...
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How to model torque and linear force of collisions for a simple 2D physics engine [closed]
I'm attempting to make a simple physics engine but chat gpt for the most part has been unreliable.
I have a 2d space (vacumm).
For simplicity I would like to model collisions between extended circular ...
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Angle for ruler falling off the table
When you place a ruler on the edge of the table so that one end is hanging off the table, and you apply a force to the hanging end with your hand, at what angle (angle between ruler and table) will ...
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What is the amount of force applied on my back while I'm brushing teeth leaning forward?
This is a question I've had for several years but never had the knowledge to calculate myself. Please keep in mind I don't have much background in physics (learned some on middle school I guess...), ...
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The forces acting on the tensegrity structure
Are these the only forces acting on the body. I assumed the COM to be somewhere there in between. since the tension in main string doesnt perfectly coincide with COM theres a small torque being ...
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What is the physical significance of the cross product of curl of a vector field $v$ with another vector field $w$?
I think if curl of a vector field v corresponds to an applied rotation, it's cross product with a velocity vector field w (say) should give something analogous to the resulting torque. Am I close?
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If the tidal bulge on the earth speeds the moon up, how does the moon move to a higher orbit?
I understand that the moon causes a tidal bulge on Earth, and this tidal bulge moves slightly ahead of the moon due to Earth's rotation.
When reading about why the moon is moving away from the Earth, ...
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Equation of Torque
The magnitude of torque is defined as the product of the perpendicular (to the object) component of the force I apply and the distance between the axis of rotation and the point of application of the ...
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Direction of the normal force [closed]
Suppose we have a bar with non-zero mass inside a hemispherical bucket fixed to the ground. Suppose, too, that there is friction between the bar and the inner spherical surface of the bucket. Part of ...
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Proof of Newton's second law of rotation for rigid body
I'm reading over my lectures notes on rigid body dynamics and I'm trying to prove as many results as possible. However I can't seem to prove that $\tau = \frac{dL}{dt}$ for a rigid body, where $\tau = ...
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Abbreviations for energy and torque
What are correct abbreviations for torque and energy in US Customary and S.I. systems?
Both include distance and force. Do we write N-m and lbf-ft for both torque and energy? I always heard (years ago)...
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What is the formula for how a force affects linear motion on a rigid body?
Say a body (two glued spheres will do) hits a ceiling, and the balls and ceiling are the only things in the universe. I translate the point of impact to the center of mass, calculate my lever arms, ...
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Picture frame hung by posts in restriction positions
Suppose you have a picture frame (or mirror) and it is held up by a string that goes around two posts which are at coordinates $(x_1, y_1)$ and $(x_2, y_2)$. The corners of the frame are at $(0,0)$ ...
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Free Body Diagram of Precessing Top
Consider a heavy, symmetric top spinning on a table, initially inclined at some angle from the vertical. Assuming this angle is fixed, it follows that the weight $\textbf W$ and normal force $\textbf ...
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Why is it possible to keep an object, say a book, horizontal while holding its corner?
When holding a book from its corner with two fingers in a pinched position, the fingers act as a sort of hinge, and the book is free to rotate about this corner only. The external forces acting on the ...
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Like force, does the rotational effect of force/torque require some finite time to travel through a real body?
Let's say I am using a long wrench to unscrew a tight bolt because the formulas developed in rigid body statics states that the moment arm should be longer for minimal force application. But how long ...
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Is there a way to explain torque and Euler's Laws of Motion from Newton's Laws
If I have a rigid rod and I apply a force $\vec F$ distance $r$ away from the centre of mass the torque on the rod is $\vec r \times \vec F$ from the centre of mass and the torque causes the rod to ...
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Weight and rate of movement
Im limited on my physics knowledge and sometimes can't understand simple laws.
When i have two 5kg objects on a "manual weight scale" then forces are equal and the scale stays in place.
...
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How can Torque and Work have the same dimensions (both can be expressed in N.m because Joules = m.N = N.m) but they represent diffrent quantitie?
So torque and work are both distance times force but how can they be so different conceptually? I understand the torque is an outer product and is a vector while work is a dot product and is a scalar ...
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How many components does the net force have on a rotating object?
I understand that there is the radial and tangential force components acting on a spinning object, but according to the attached image from my book, there is a third component F_1z that is ...
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What are the physics behind the torque trick that uses a single match to hold a water bottle?
https://youtu.be/CO5YUrbFTig?si=6HBL6tsSZqS6EWkq
I have seen a lot of videos about the same physics trick lately.
How would I be able to do this trick myself and find out what forces are interacting ...
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Convention or reality?
In case of a disc rotating about an axis perpendicular to its plane passing through its centre of mass, the torque vector points up or down depending upon direction of rotation. Is it just convention, ...
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Confused with the effects of moment of inertia and torque
According to the definition of torque, if the distance from the pivot is large the force required to apply will be smaller to move with the specified angular velocity/acceleration.
And we can ...
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Torque of a lever with two fixed points at an acute angle
Is the torque at the yellow fixed point calculated using the perpendicular distance between the yellow fixed point and the red weight, or using the distance between the yellow fixed point and the blue ...
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Can we model the pitch up of an aircraft due to sudden application of brakes while it is rolling down an inclined using angular impulse method? [closed]
Consider an aircraft parked on an inclined plane. Due to a mistake by the pilot the brakes were released, and the wheel chocks were missing. When the plane started to roll down, the pilot applied the ...
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Can someone please elaborate an answer about torque? [duplicate]
Please explain Michael Seifert's answer here
I think $x,y$ are distances but what is $d$?
How did he get this formula?
x
cos
θ
+
d
sin
θ
Does this ...
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Normal reaction exerted by a rolling object
If we take a disc of mass M and radius R and assume that the disc is performing Combined rotational and translational motion on a frictionless flat surface. then if we take a point at the top of the ...
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Why does torque increase with radius or distance from the centre?
Why is it that making a perpendicular force farther away from the axis of rotation increases the rate of change of angular momentum (hence, torque)?
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Maximum Velocity of Car in Circular Motion Without Tipping?
We are tasked with finding the maximum velocity of a 4-wheeled vehicle undergoing circular motion without tipping (assuming that the force of gravity will act at the car's center of mass and the the ...
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Why is the output torque less than the input force of 20N applied from a wrench having length of 0.8m?
A wrench is of length 0.8m, or any number below 1.0m, I am exerting a force of 20 Newtons on the point A (one end of the wrench), on point B there is a bolt (on other end).
If I calculate the Torque ...
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Calculate rotation from net torque and inertia matrix
I am trying to grasp the concepts of forces applied to a rigid body resulting in a net change of the rotation of the object.
This is not a home assignment and I read some resources on both the web and ...
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Is Joule equivalent to Joule/radian? [duplicate]
The work a constant torque does when it moves a particle through an angel $\theta$ is given by $\tau \theta$. The work is measured in Joule, so the torque should be measured Joule/radian, but the ...
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Equations for Torque Capacity and Bolt Clamping
I am doing research into how I can best approximate the torque capacity of several components bolted together in an assembly and specifically when a pattern of bolts is holding several parts together ...
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Problem while calculing the bending torque of internal air pressure in a soft actuator
this is a question I cant resolve while looking a paper I needed for my undergraduate thesis.
In this image (from Modeling of Soft Fiber-Reinforced Bending Actuators, Panagiotis Polygerinos et al.), ...
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Can the brakes of a Semi-trailer truck overcome the torque of the engine? [closed]
On the average Semi-trailer truck, assuming an average load, can the engine overcome the brakes and continue spinning the wheels despite the operator applying the brakes fully?
This would be assuming ...
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Torque profile with fixed boundary condition
I am trying to find a simple treatment of elasticity theory of a scenario where I have a thin rod attached to a disc (radius $r_0$), and the disc is held fixed at its edge. Now I apply some torque to ...
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Rotational Equilibrium With Forces acting on only two points
Imagine a rod that is held at angle to the vertical by some hook. The rod is in equilibrium. There would be three forces on this rod - Normal contact, Friction, and the weight of the rod.
I struggle ...
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Misconception About Torque Log cutting example
LOG CUTTING
"Three friends go camping in the forest with their families. They start collecting wood to make a fire. They find a large, branchless log in the forest. One end of the log is very ...
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Sign of distance/arm when finding moment/torque
I know that $M=Fd$, but when I have a negative moment, does the sign of the moment matter when I'm calculating for distance? If yes, then what would it mean when distance is negative?
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What causes an arrow to rotate? [duplicate]
My intuition:
In a system without air resistance, I would expect an arrow shot at an angle with its head pointing upwards to follow a ballistic trajectory without rotating around the horizon - because ...
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Calculate weight distribution on 2D plane
I am trying to figure out how I can have a formula for the weight distribution on a square. But let me just describe what I am doing,
We have the classical horizontal beam support problem
And I we can ...
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What exerts torque on a pulsar? [duplicate]
I'm modeling a pulsar as a rotating compact body with frequency $\omega(t)$, and magnetic dipole moment misaligned from the axis of rotation by angle $\chi$. It's straightforward to calculate the ...
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Is Torque always defined about the axis of rotation?
My professor told me torque can be calculated about any point in space, but would such a torque ever make sense even if the particle is rotating about some other axis, on which the point does not lie?
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Choice of axis in analysis of gyroscopic precession
In many demonstrations of analysis of gyroscopic precession, the analysis goes on by choosing two axes, one about which angular momentum is calculated, another about which torque of gravity is ...
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Confusion about torque [duplicate]
Consider a free body, not hinged about any point. If a force is applied to one end of the body, the body has a net nonzero torque about many points in space. About which will it rotate? Am I wrong in ...
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What does the geometric product between displacement (or maybe position) and force vectors mean?
So work is measured in joules, which is newton * meter, and it is calculated by taking a scalar product between displacement and force vectors.
And torque is very similar, it is newton * meter too, ...
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How to calculate total moment around $z$-axis when the armlengths are not the same for all motors on a hexacopter?
I wonder how I can calculate the total moment around $z$-axis at a given rotational velocity for the motors on a hexacopter. My intuition tells me that motors that are more distant to center of mass ...
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Axis of rotation of a spool unwinding and falling under gravity
There is a problem that asks for forces that apply torque around the axis of rotation on a spool of string that falls and unwinds under gravity. The spool falls straight down with a vertical string. ...