# Questions tagged [torque]

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

154 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
119 views

79 views

### Normal reactions with moments

A uniform ladder, $AB$, is leaning against a smooth vertical wall on rough horizontal ground at an angle of $70°$ to the horizontal. The ladder has length $8\ \rm m$, and is held in equilibrium by a ...
68 views

### Angular Impulse equations for rotational dynamics

Consider a 3d rigid body at rest initially, assuming no net external forces acting on it. It is set in perpetual rotation along one of its principal axis. Now an angular impulse (which is a vector) ...
38 views

### Mechanics, Torques in accelerated frames

Consider the following problem: My first attempt of a solution was taking moments about Point O and solve for variables by setting the final torque to zero. After consulting the text book and quoting ...
59 views

### Does the hinge reaction do any work?

I was doing some questions in rotational mechanics and I am not able to understand the concept behind hinge reaction which acts on a rod suspended at a point. I am taking a simple example here. Let's ...
39 views

### Can anyone explain me how do I calculate torque?

For my gate automation project, I estimated the amount of force required (in order to estimate the torque) to pull my gate with a spring balance. The display on the spring balance read $2 \text{ kg}$. ...
58 views

### Gravitational attraction between a particle and a bar

I'm trying to solve this problem from the book "Fundamentals of Applied Dynamics" by R.A.Tenenbaum. I start it by trying to find the resultant gravitational force by the means of integration. d\...
46 views

### How to calculate torque for a linear slide pulley?

I have a linear slide pulley system like in the picture (the string on the right will be attached to a spool, which is attached to a motor) and I'm trying to determine the right motor to buy to power ...
850 views

### What causes this corkscrew-shaped object to rise up in a stream of water falling down?

A corkscrew-shaped object is floating in a tub of water. When water is poured into the tub from some height, the object starts rising up vertically in the stream of water. The water stream is falling ...
22 views

### Static Equilibrium: cable sag considering equal pulling forces on extremities

When considering a cable with a non-negligible mass and an equal force pulling the cable at both extremities, how can one compute the mid-span sag or a sag function whilst accounting for this pulling ...
53 views

### Plane rotation of a bar in a viscous fluid, computation of the torque

Assume a rigid, cylindrical bar which rotates around $\Omega$ (axis of a engine). The bar is immersed in a fluid of kinematic viscosity $\nu$ and has a plane motion. What is the torque applied to ...
49 views

### Torque on a quarter-wave plate… Where is the force? Where is the moment arm?

If you shine circularly polarized light (carrying angular momentum) through a quarter-wave plate, the light will emerge as linearly polarized light (carrying no angular momentum) from the other side. ...
64 views

### Transverse speed of hamster in wheel as function of theta

i need help with conceptual understanding of how this system works. A small animal is running in a wheel with radius R, (and 0 mass). When the animal is at an angle $\theta = \alpha$ measured from ...
79 views

### Finding the state space representation of a dynamic model with the force and angle as control inputs vector

I am trying to design a controller to control the angle of the force on my mobile rigid body. I some questions: I am not sure how to write the state space representation with the force, $F$ and angle,...
65 views

### Calculus of torque to move a small vehicle

I have a to choose two DC motors in order to carry a vehicle. I assume that the mass of the whole vehicle (all components included) is 1Kg, the surface is flat and made of wood, the wheel coupled to ...
39 views

### How to account for forces between connected bodies?

So lets say that I have a system which consists of two 1kg spheres (1 meter radius) which are connected by a massless rod which keeps the centers of the spheres at a fixed distance of, say 10 meters. ...
50 views

### Spinning ball gently lowered onto rough floor

Trying to reconcile the real world observation with first principles, here is a problem I came across. Consider a ball initially rotating with axis parallel to the floor lowered gently onto a rough ...
405 views

### Torque applied over center vs. off-center

I have a tool that loosens a bolt with the torque applied over the center of the bolt (box end wrench). I have a different tool that uses a socket which applies the torque (has the ratchet connection) ...
287 views

### Angular velocity - Gyroscope

I am currently researching the gyroscope on my own and i came across the concept of angular velocity. The torque ($T$) on a gyroscope is caused by $R\cdot F$, where the force i consider it to be ...
2k views

### How to calculate theorectical engine max. torque from max. power and RPM?

I'm trying to come up with a formula to estimate an engine's maximum torque (and at which RPM) given other values and some assumptions. I'm approximating an engine's torque curve as 2 linear ...
259 views

### How to spin a fidget spinner with maximum velocity?

Physics doesn't always come in the form of books. It also comes in the form of toys. So, I came across this fascinating toy that spins two minutes straight when given a spin. I got a chance to use ...
94 views

### If the bicep connects closely to the elbow joint, would the bicep need to exert more or less force to lift an object?

I would like to know whether a less or large amount of force is exerted by the bicep to lift and hold an object if the bicep is connected close to the elbow joint (fulcrum) than if the bicep is ...
40 views

### Do couples act in current/ampere balances

I understand that the basic principle of a current balance is that mg=BIl when equilibrium is reached and thus B can be found. This means that torques must act when the mass is placed on the balance ...
96 views

### Determining the mass of my car via m = F/a

I'd like to do something unconventional. I'd like to weigh my car by hitting the gas. I have an accelerometer in my phone (a). I'm trying to determine the force the car is exerting (against the road, ...
192 views

### Equations of motion for a torqued spherical pendulum

I Want to simulate a spherical pendulum with a torquer on it, i.e. the angles of the pendulum change not only due to torque generated by gravity, but also by a torquer attached to the top of the ...
263 views

### Find torque due to Lorentz force - Wrong result

Current I is coming from the Z axis and then it flows out uniformly towards the circumference of this disk. The disk has thickness t and Radius R. There is also a constant B field in the Z direction(...
1k views

### Rotating disc ('fidget spinner') off of its axis of rotation (while it is spinning)

A craze of 'fidget spinner' toys has broke out recently in my hometown. If you are unfamiliar, they are basically just discs with a fixed joint and ball bearing at the center so you can rotate them ...
237 views

### Summation of Forces through a Lever Linkage

I'm trying to brush up on some of my force and torque stuff so I can do some modelling in software. My problem is, it's been a while and I'm unsure of how correct my work is. I have a system as ...
129 views

### Effect of forces inside a sphere

What would be the effect of applying two parallel forces of the same value at opposite points of the equator inside a sphere? Common sense tells me that it wouldn't move, but it seems that it could ...
265 views

### The torque created using an oval chain ring

I have seen the explanation on "How bicycle gear works?" but this seem to be using a standard round chain ring. I would like to know if there is any difference when an oval chain ring is used. As I ...