In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment, moment of force, rotational force or turning effect, depending on the field of study. The concept originated with the studies by Archimedes of the usage of levers. Just as a linear force is a push or a pull, a torque can be thought of as a twist to an object around a specific axis. Another definition of torque is the product of the magnitude of the force and the perpendicular distance of the line of action of a force from the axis of rotation. The symbol for torque is typically
τ
{\displaystyle {\boldsymbol {\tau }}}
or τ, the lowercase Greek letter tau. When being referred to as moment of force, it is commonly denoted by M.
In three dimensions, the torque is a pseudovector; for point particles, it is given by the cross product of the position vector (distance vector) and the force vector. The magnitude of torque of a rigid body depends on three quantities: the force applied, the lever arm vector connecting the point about which the torque is being measured to the point of force application, and the angle between the force and lever arm vectors. In symbols:
{\displaystyle \tau =\|\mathbf {r} \|\,\|\mathbf {F} \|\sin \theta \,\!}
where
τ
{\displaystyle {\boldsymbol {\tau }}}
is the torque vector and
τ
{\displaystyle \tau }
is the magnitude of the torque,
r
{\displaystyle \mathbf {r} }
is the position vector (a vector from the point about which the torque is being measured to the point where the force is applied),
F
{\displaystyle \mathbf {F} }
is the force vector,
×
{\displaystyle \times }
denotes the cross product, which produces a vector that is perpendicular to both r and F following the right-hand rule,
θ
{\displaystyle \theta }
is the angle between the force vector and the lever arm vector.The SI unit for torque is the newton-metre (N⋅m). For more on the units of torque, see § Units.
I calculated the total moment of inertia of the system to be ##2ml²Sin²θ##, so the angular momentum is ##2ml²ωSin²θ##.
To get the torque on the system I need to differentiate the angular momentum but I don't have any time dependent terms. What should I do?
Hello,
I am confused about something. I will take the time to work it out, but right now, I am using it to remember. And I am now confused.
Go here:
https://www.smlease.com/entries/mechanism/gear-train-gear-ratio-torque-and-speed-calculation/
Scroll down to the section on...
Hello my dear physicists,
I'm trying to model the varied generated (needed)Torque to rotate a washing machine Drum during a Washing Process
so i assumed that the Model has as Input the target vilocity and as an Output the new needed torque to rotate the Drum(to be as a input for the motor...
Hi everyone I can't understand how normal force produce torque isn't normal force acts normally on the plane so the perpendicular distance in case if it was like block will be zero, so normal force doesn't produce torque. "case of box"
I tried using r * f * sin theta and calculated this:
1.14 m * 9.80 m/s/s * 7.78 kg = 109.7 N*m
this was wrong; I needed three significant figures so I did 1.10E2 N*m which was also wrong.
Since the torque is due to gravity; would it be -1.10E2 N*m since it’s angle is -270° which is -1?
If I'm to choose a motor to suit a vertical load (torque)-see the attached picture for more illustration-. What is the criteria should i follow?
After i have done the math for the weight of the object to be rotated, the torque to rotate the load is to be horizontal, and i only have the weight...
Free body diagram is below, but I have confusion about the tension. The tension on the block and pulley should always be the same by Newton third law. so T1=T1' and T2=T2'.
Part B) The system is in equilibrium so net torque on each pulley is equal to zero. Therefore T1'=T2' and T2'=T3.
Applying...
Okay let's say we have a wheel attached to a fixed axle, free to spin, ignore friction and we apply a force on the edge of the wheel. That force creates a torque, does the axle have an opposing force to keep the wheel/axle assembly from accelerating linearly?
Ive learned on this forum that when...
I'm using a servo to lift a pen. The pen and a bit of mechanism weights 35g.
The servo I use to bring the pen up and down claims to have a torsional moment of 1.5kg/cm. Sometimes they call it torque in the specs. But surely that does not mean they are claiming that if I hung a 1.5kg weight a 1...
Hello everyone !
I've got a problem in engineering class with a braking system (picture linked).
In the first part I calculated the friction force $$ \vec{B} $$ with components :
T (following y axis) : 2073.6N
N (following x axis) : 5760N.
For the first question I struggle a lot because I...
Not sure how they obtained an answer of (2meukenetic *Mg/R^2)*r^2 dr = dt
When they say disk I am assuming it's not ring shaped. So since F * Dr= DT where I guess F acting on a small point on the disc is constant from the table top. And Dr is the variable distance from a random small point from...
I'm trying to find out if my motor can rotate a robotic arm upwards from a resting position (we can assume the arm is a cylinder for simplicity).
The cylinder has an outer diameter of 5.6 cm , and an inner diameter of 5.0cm
Therefore its cross sectional area in that case should be
pi(2.8)^2 -...
let's say we have a robotic arm, connected to a servo motor. the servo motor is rated at 500 kilogram-centimeter. the robotic arm lifts something upwards.
will the torque remain constant? if so, torque equals force times distance to point of application of force time sine angle, will the angle...
There's a micro motor with a gear ratio of 298:1 and there's a servo with a ratio of 188:1.
The first runs at 12v and the other at 7.4v.
How is it that the motor with the bigger gear ratio has only a 70 oz-in torque, while the second motor has a 560 oz-in torque?
First motor ...
I've been working on this problem for a couple days now and I'm clearly missing something.
I first went ahead and solved the triangle. Hypotenuse is 5, height is 4, the last side is 3 and the angle is 53 degrees.
I went ahead and did the sum of forces in the y direction = Fn - Fbucket - Fearth =...
In studying gyroscopic progression, the angular momentum vector is added to the torque vector. As intuitively these two vectors seem to be qualitatively quite different, how do we know that both vectors are in the same vector field and that they can be manipulated using the rules of vector...
Homework Statement: The torque is removed when the disc is rotating at 8.0 rad s-1. An opposing torque of 14.5 N m is applied to slow the disc down. Calculate the number of revolutions the disc makes after the second torque is applied, before it comes to rest.
Homework Equations: T=Is
W=Wo...
I converted the amount of rotations completed in 5 seconds into radians.
23.4 rot * 2pi = 147 rad
I found the angular acceleration of the object in the first 5 seconds it was speeding up.
Wf = Wi + at
a = 5.881 rad/s^2
I then used the moment of inertia given in the problem to solve for torque.
T...
As per (b) in the above image, or easily solved with t=rFsin(theta), the perpendicular force is 260N.
When inputting that value into the equation for torque, the value for torque is 520Nm, as per t=2.00*300*sin60.
Because the wedge prevents the door from moving, the torque on/at the doorknob...
Homework Statement: Hi there.
I am new to this forum, but I joined just to ask some input from anyone who may be kind to help.
I have this attached file where you can see all the values and equations I have used but there is one bit where I need help. finding Torque on Shaft B, I appreciate...
torque=Force*radius*sin(theta)
center of mass x direction = ( 0(6 x 10^9 kg)+ (118m)(6 x 10^9 kg)+ (236m)(6 x 10^9 kg) )/(3(6 x 10^9 kg)) = 118m
center of mass y direction = ( 0(6 x 10^9 kg)+ (140m)(6 x 10^9 kg)+ (0)(6 x 10^9 kg) )/(3(6 x 10^9 kg)) = 46.7 m
radius = (118^2 + 46.7^2)^(1/2) =...
moment of inertia = (1/3) (2.1kg) (1.2m)^2 = 1.0 kgm^2
center of mass= (0.6i, 0j)
magnitude of the gravitational torque=9.8m/s^2*2.1kg*0.6m= 12.34N*m
position of the new center of mass now :
x direction = cos(20)*0.6m=0.56m
y direction= -sin(20) * 0.6m = -0.2m
change in gravitational...
NOTE: THIS IS THE GRAPH PROVIDED
At first I approached this problem attempting to solve for the total work done, using the formula
Wtotal = Wmaxforce - Wfriction
I then subbed into the formula, representing the values of work as their torque value times theta, which gave me a longer algebraic...
∫ λ(x)=0.2 kg/m + 0.061(x/L)^2 kg/m = 0.2(x) + (0.061/3) (x^3) /(1/L^2)
mass of rod = 0.2+ (0.061/3) =0.22 kg
inertia of rod through nail = (1/3) (mass) (L)^2
inertia of rod through nail = (1/3) (0.22kg) (1m)^2 = 0.073 kg*m^2
torque magnitude = (53N) (0.5m) = 26.5N*m
angular...
Earlier I read that as distance from centre of axis of rod increases it's inertia increases but why does torque increases isn't it like that if inertia increases for same force the less force should be produced?
I know that I have to calculate force that is generated by water. However, I do it wrong way.
## A = \pi r^2 ##
## v = \frac Q A = \frac Q {\pi r^2}##
## F = P t = mvt = ...? ## - have problem with mass. and is it even correct way?
if I can calculate F - its easy afterwards...
##\tau = F l ##...
Hi everyone, I want to rotate this (see attached image) platform at a speed of 20 RPM. To this end, I have to calculate the torque and power of a motor required. I have done preliminary calculations, however the numbers I'm getting doesn't seem right. For example, I'm getting that the torque...
Hello guys, i need some enlightenment (help) to solve this problem :H, maybe someone here have mastered physics or engineering can help me to break this problem !
I already tried to seek the answer, but i face dead end and really frustating because of it o_O .
So the problem is "how to get...
Summary: Consider a train carriage rolling along a curve that forms a left turn on the track. The carriage speed is directed along the y-axis (into the plane of the paper) in the figure. The trolley will have a tendency to curl in the curve in the specified direction. A flywheel is inserted...
We first determine the Laplace force for each value ##\alpha##.
$$F_{\alpha} = 5(0.3)(0.4)\sin(\alpha) = 0.6\sin(\alpha) \ \text{N}$$
We then calculate the torque at angle ##\alpha##.
$$\tau_{\alpha} = \frac{a}{2} F_{\alpha} = 2.5 F_{\alpha} \ \text{N.m}$$
Then we just plug in ##\alpha## and...
Hello all,
This is my first post on here so sorry if its not the greatest.
I am starting to make a car based video game for the ios in which you are able to customise cars and race them. One feature i wanted to include in this game was the ability to create unique engines. I don't want it...
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I have a hollow cylinder (pipe) that needs to spin 25 RPM:
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- ID = 48 mm
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Hi,
Say there's a gyroscope with moments of inertia Ix, Iy and Iz spinning around a vertical z-axis (see attached illustration) with a given angular velocity ωz. Notice that the gyroscope is floating in space as in that there's no gravity acting on the gyroscope.
Now I apply a torque τx...
On speeding up:
τload - τfriction = Iαup
On speeding down:
τfriction = Iαdown
If i substitute τfriction from speeding down to speeding up equation, i get moment of inertia:
I = (τload)/(αup+αdown)
But, is this allowed? Does friction torque in speeding up is equal to friction torque in...
Want to let the steel ball move upwards at a uniform speed, how is the torque of the spiral tube calculated?
The parameters can be assumed by themselves.
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Hello All,
I am designing a robot that has these dimensions, I need to work out the torques around T1 to T6, I am unsure of the best way to do it, ie do I do a net torque calculation around the torque to be found or is there a better way.
W1 to W4 =
0.53955 kN
W5 =
14.44032 kN
W6 to...
hi,
I'm working on a rotational system, and my goal is to rotate a 500kg(1100lbs) load to 90° in 1.5 seconds. Inertia of load makes system hard to accelerate and decelerate. I designed a gear system but still motor needs too much torque.
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Homework Statement: Finding the braking torque applied on a moving disk as a result of the Eddy Currents
Homework Equations: $$F = \sigma v V B^2$$
So right,
Basically my problem is how to find the torque exerted by an eddy current braking setup.
My setup consists of a disk rotating on an...