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

learn more… | top users | synonyms

1
vote
2answers
267 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 ...
0
votes
1answer
153 views

How can angular velocity be constant even when there is a torque by friction?

A cylinder at rest lying on a rough ground is given an impulse which imparts a translational velocity (no angular velocity) to it. The question goes ahead with finding time after which rolling starts ...
0
votes
1answer
21 views

How to apply torque impulse

In the below question, can we apply conservation of Angular Momentum? If not, why? Moreover how do we apply Torque impulse to the system ? The contact force between the cylinders will be normal to ...
0
votes
2answers
253 views

A lever arm-definition question

My question is regarding Torque, and specifically the definition of the lever arm. As far as I've understood, the lever arm is the line perpendicular to the line of action to your reference point. ...
-1
votes
0answers
23 views

Torque Problem (tension and thrust) [on hold]

A crane boom which weighs 200 lb and which ia 10 ft long is supported so that it makes an angle 50° with the supporting wall and so that the rope makes an angle of 70° with the wall. If load of 700 lb ...
-2
votes
0answers
17 views

Torque (Distance × MomentArm) [on hold]

A bar 2.0 m long makes an angle of 30° with the horizontal. A vertical force of 40N is applied 0.4 m from the upper end. Calculate the torque due to this force about each end.
1
vote
2answers
119 views

How bicycle gear works?

Based on the concept of the moment of inertia, my book gives the following relationship between the size of gear and amount of torque supplied to the drive wheel: Because it [outermost gear] had ...
0
votes
1answer
12 views

Why doesn't Torque of masses on a pulley depend on the friction between the rob and the pulley according to a question in the physics 1 book

What I don't understand about this question is: why is the torque of the masses on the pulley equals the weight of each mass times the radius. I thought that the torque on the pulley from the ...
0
votes
0answers
3 views

Measuring thrust with vertical torque

I would love to measure the thrust of a series of small rocket motors for a science project but having trouble figuring out the math.. A rocket motor with mass m1 is r1 meters from axis of rotation ...
0
votes
2answers
34 views

Damped Pendulum (generalised)

I know the differential equation for the swinging of a simple pendulum: $\displaystyle\frac{\partial^2\theta}{\partial t^2} + \left(\frac{g}{L}\right)\sin\theta = 0$ where: $L$ is the length of ...
2
votes
2answers
147 views

Which moment of intertia do I need to calculate torque

I'm trying to calculate the torque needed to rotate an array of solar panels. I've found some formulas for calculating torque, but they require moment of inertia. I designed this array in Autodesk ...
-1
votes
0answers
18 views

Torque required to rotate Davit [closed]

I need to know torque required to rotate davit with max. Capacity of 500kg at 2.47m from a column. Is there any other physics available other than friction coefficient of steel multiplied by normal ...
1
vote
2answers
192 views

What is the effect of torque steering on a motorcycle with a long wheel base?

From experience, it appears motorcycles with a large wheelbase coupled with a long handlebar (say a modified Harley Ape Hangar) shows a noticeable tendency to veer to a side during acceleration vs a ...
0
votes
1answer
141 views

Calculating output forces of bicycle wheels

Based on the force on the rear gear $F_t$ and the radii of the rear gear $R_g$ and rear wheel $R_w$ , how would you calculate the force the bicycle exerts on the ground when it is accelerating? I ...
1
vote
1answer
332 views

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

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 ...
-1
votes
0answers
30 views

Force required to swing gate open/close

I need to know how to calculate the force required to swing the gate open / close. If it is moving straight, we can use f=ma, but how to calculate for swinging motion? When I open or close the gate, I ...
1
vote
2answers
30 views

Torque: The T-shaped stick problem

This is a problem that I have been unable to solve for some time. Imaging a T-shaped stick, as shown in below image, which do not deform in any appreciable way and has pivot point at the tail of the ...
0
votes
1answer
20 views

Why, here, the torque with respect to bob is zero?

here, as you see, is a diagram of a pendulum with moving pivot along x-y surface. This picture was obtained from a journal in which this equation was written: $$F_x l \cos\theta = F_y l \sin\theta ...
4
votes
2answers
11k views

Torque And Moment Of Inertia

I am reading the two concepts mentioned in the title. According to the definition of torque and moment of inertia, it would appear that if I pushed on a door, with the axis of rotation centered about ...
0
votes
2answers
21 views

What determines whether a mobile will hang in stable or unstable equilibrium?

Asking for a friend trying to make a Calder-style hanging mobile: https://www.google.com/search?q=mobile+calder&tbm=isch I understand torque just well enough to get it to balance (theoretically). ...
0
votes
0answers
22 views

Conservation of angular momentum in a system under torque

Let's say we have a particle $A$ like this which is located in the disk $c$. Consider that the particle itself is not moving, but in general it is constrained to the semicircle $d$, in that if it ...
0
votes
2answers
39 views

Why can't a force between two particles exert a torque?

Let's say I have two particles which exert a mysterious force between them. Say they lie on the x-axis. Newton's 3rd law tells us that the force on the two particles due to the other must be opposite ...
0
votes
1answer
170 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 ...
0
votes
1answer
264 views

difference between magnetic dipole moment and torque on a magnetic dipole?

I am a bit confused. What is the difference between magnetic dipole moment and torque on a magnetic dipole ?
0
votes
1answer
205 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 : ...
0
votes
2answers
40 views

Why don't barbells tip over when a 45 is placed on one side?

A standard barbell is 45 pounds, as is the heaviest weight available in most gyms. When a weight is placed on the side of a barbell, some of the barbell is to the "outside" of the weight, like so, so ...
3
votes
4answers
531 views

Would this box on the floor rotate based on friction?

There is a floor that friction is proportional to its velocity (like $F=-kv$) and there is a box with its width as $l$ and its height as $h$. (you may assume that $l$ is longer than $h$). It is on the ...
1
vote
2answers
32 views

Direction of torque due to magnetic moment

I have a problem with determining the direction of torque due to magnetic moment on a current loop. Since the torque is defined as $$ \tau = p_m \times B $$ so I guess the direction of the torque ...
1
vote
0answers
26 views

Parallel axis theorem non-uniform density [closed]

The parallel axis theorem says that if the moment of inertia of a body rotating about the body's centre of mass is $I_{cm}$, then the moment of inertia of the body rotating about an axis parallel to ...
0
votes
2answers
61 views

What exactly is a torque?

I know there are a number of questions concerning torque on this site but I still don't quite understand what it is. A video by veritasium on gyroscopic precession ...
0
votes
4answers
204 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 & ...
3
votes
1answer
30 views

Mechanics principle

When two forces of equal magnitude, opposite in direction and parallel act on an object, the object will rotate without having translational speed. On the other hand, when three concurrent forces ...
3
votes
3answers
545 views

Why does the moment of force (aka. torque) depend on the perpendicular distance?

Couyld anyone explain how the lecturer concluded that $$(\underline{r_2} - \underline{r_1}) \times \underline{H} = \underline{p} \times \underline{H}$$
1
vote
1answer
21 views

Four bar linkage moment transmission

The question is. I know the angular velocity of $d$ after applying dynamic mechanics and the constant angular velocity of $b$ of $2\pi\ \text{rad/s}$ and I know the input moment of the power source ...
3
votes
4answers
12k views

What is the relationship and difference between BHP and Torque?

I've recently been looking into performance figures for various auto mobiles, and I see the terms BHP and Torque used quite often, but I can't say I really understand the terms, or how they relate to ...
1
vote
1answer
58 views

How do I handle elastic contacts in a simulation with friction [closed]

I'm trying to simulate a wheel as it hits the ground. Problem 1 Suppose a disc is dropped from a height. It has initial velocity of $-x,-y$ caused by throwing and gravity. It has no initial angular ...
0
votes
1answer
31 views

Is a rotor balanced at constant angular velocity?

I have an asymmetrical rotating part. It vibrates its housing and emits audible noise. I need to add weights to ensure smooth rotation. However, I am constrained in which regions I can add ...
0
votes
0answers
18 views

Weight placement of turning motorcycle and traction

In the motorcycle racing world it seems that there's advice that one should place their weight on the outer foot rest when turning at high speeds, from some forums I've been looking at it seems like ...
0
votes
0answers
16 views

Forces in material removal (cutting, grinding, sanding, etc.)

A. Suppose a circular saw is spinning at a certain angular speed. When it starts to cut into the material, removing chips of the material or abrading it, the speed drops. The drop in speed depends on ...
0
votes
0answers
45 views

What is the derivation of $r*F=Iα$? [duplicate]

Please give me the derivation of the formula r*F=Iα for extended body. where, F=applied force r=distance between point of rotation & point where force is applied I=moment of inertia of the body ...
1
vote
1answer
39 views

Force (torque) to break a bike handlebar? [closed]

Few weeks ago a neighbor manage to hit my bike with his car while the bike was parked next to a wall, check the picture. One side of the handlebar was at the wall and the door of his truck hit ...
4
votes
3answers
5k views

Which force makes a wheel roll down the hill? What causes friction?

A wheel rolling down a hill has two axis of rotation. One is where the center or mass is and the other is the point of contact with the surface which acts as a fulcrum. I was trying to understand ...
-1
votes
1answer
30 views

can a single force rotate an object. not a torque

Can a single force (not a torque) rotate an object? How can the bar below fall given the force $\mathbf F$?
1
vote
1answer
40 views

With radian as a unit, should action and angular momentum have the different units?

If one accepts radian as a fundamental unit, does it make sense that action and angular momentum have units differing in radian to the power of one? The same question applies for energy and torque. ...
1
vote
2answers
67 views

Angular momentum changes depending on orign

Consider the image below where we have two point masses $m_1$ and $m_2$ with different masses which are rotating around a fixed axis with angular velocity $\omega$. If the origin is placed on the axis ...
7
votes
3answers
2k views

Apparent violation of Newton's 3rd law and the conservation of angular momentum for a pair of charged particles interacting magnetically

Consider a system of the two identical point positive charges situated in free space (isolated from influence of any other external fields) as shown in the figure below. Particle 1 is at $(a,a,0)$ and ...
0
votes
0answers
11 views

Stick stands in the corner then starts to fall, when will it detach from the wall? [duplicate]

A thin homogeneous stick stands on the smooth(no friction) floor, leaning against a smooth wall,stands absolutely vertically. (Imagine a corner).Then it starts to fall(with zero initial velocity).What ...
1
vote
1answer
25 views

Torque as if magnetic force were concentred in mean point

From what I see in my textbook and several on line resources (such as this, p. 8-8), I am tempted to think that the magnetic force $I\boldsymbol{\ell}\times\mathbf{B}$ acting on a straight conducting ...
1
vote
1answer
47 views

Rotational equilibrium Paradox

A block of mass M and height h is moving on a rough surface of coifficent of friction 0.5 .The block is moving with a velocity v at some instant. if we balance the torque due to frictional force and ...
0
votes
1answer
21 views

Changing angular momentum with no forces to do torque

Suppose a particle of mass $m$ moves in a straight line at velocity $v$ some distance away from an axis, as shown here at times t1 and t2 (where the axis of rotation is located at the origin of the ...