Torque Definition and 1000 Threads

Homework Statement A uniform beam at equilibrium is suspended by a cord at X which is 2m from one end of the beam and and 3m from the other end. There is a mass of 28N attached to the 2m end and a mass of 10N on the 3m end. Determine the weight force of the beam Homework Equations...

Hi, I have a problem that I've been trying to figure out for a while but cannot seem to get on my own. I'm trying to figure out how much power will be generated in a motor given a certain amount of torque. The problem is, to find the amount of power output , I also need to know the rotational...

So if a ball is rolling down a ramp and not slipping, you have two torques... the mg*sin(theta) portion of gravity and the (mu)mgcos(theta) for friction. My question is this: Does this friction force remove energy from the ball? (I know it affects the balls rotation but this is just changing...

I'm confused about this rolling without (or better with) slipping situation. Suppose to have a disk with initial velocity ##v## and angular velocity ##\omega##. The motion is to the right but the angular velocity is counterclockwise. There are no forces acting on the disk besides the kinetic...

Homework Statement Word for word, from the problem: "A person’s center of mass is easily found by having the person lie on a reaction board. A horizontal 2.5-m-long, 6.1 kg reaction board is supported only at the ends, with one end resting on a scale and the other on a pivot. A 60 kg woman...

Homework Statement A transfer car moves concrete slabs. Given values are wheel diameter D, shaft diameter d, rolling resistance FL , speed v, car weight mv , load weight mk , output power P at rotation speed n, average torque Mm , motor moment of inertia Jm , fan moment of inertia Jt and...

Hi, I'm a beginner on hydraulics and have been reading up a lot of literature. But I'm not sure if my assumptions are accurate and I hope I can discuss with other forumers here! My apologies in advance if my questions seem silly! Background: My goal is to drive a hydraulic motor at constant...

Hi, if I have a block of metal with a quarter circle curve cut out of it, and a metal roller of matching radius that contacts this curved piece, what are some ways I could go about measuring the friction between these two surfaces? The roller is fixed and the block is pushed into it with a...

Hi guys, Im trying to build an electric wheelchair with mecanum wheels, and as you might know, each of its 4 wheels has to be independently powered for the chair to have holonomic motion. With my desired speed to be around (brisk) walking speed only, say 1.15 m/s, and my mecanum wheels sized...

Torque ##\tau## should be in the same direction as the change in angular momentum ##\Delta L##, but the following example seems to suggest otherwise. Consider a cone rolling on its side without slipping on a flat surface. Let the apex be the origin and the initial coordinate of the center of...

Homework Statement What is the angle of twist at gear A relative to the motor? (Round to the closest 6th decimal) Homework Equations I know to find the angle its θ = ∑ (TL/JG) but it can also be θ = Lτ/Gr The Attempt at a Solution So i used both these equations, and I got...

Homework Statement A 5.00-m long uniform ladder leans against a smooth wall and its base rests on a rough floor. The ladder has a mass of 18.0 kg and its base is a distance of 2.30 m from the wall. A person of mass 70.0 kg climbs 2.50 m up the ladder. If the ladder is to remain in place, what...

For the rotation of a rigid body about a fixed axis z the following holds. $$\vec{\tau_z}=\frac{d\vec{L_z}}{dt}= I_z \vec{\alpha} \tag{1}$$ Where \vec{\tau_z} is the component parallel to the axis z of a torque \vec{\tau} exerted in the body; \vec{L_z} is the component parallel to the rotation...

After completing two experiments to find the shear modulus of a beam, I found two very different results. For test 1, we twisted the beam slowly at very small angles (0.005 - 0.03 rad), only in its elastic form. The torque was found using a torsiometer . In test two a replica of the beam was...

Hi, I am required to design a tandem bike where multiple torque inputs will be present at different speeds since persons on the bike will not be cycling at the same rotational velocity. From my understanding of freewheel clutches to transmit all the torques produced by the cyclists using...

We have a solar tracking device that uses phase change of paraffin wax when heated inside a solar receiver. With a helical slot in a torque tube we can translate the expansion into rotational motion. We use this rotation to point solar panels at the sun, thus generating more electricity. Look...

Hello all, I am trying to figure out how to calculate the torque on a cam shaft. Say we are looking at this cam and cam follower: If we know that the total force downward caused by the cam follower is, let's say, 50lb, how do I determine the torque required of the cam shaft to rotate the...

Hello! Before I start I want to apologize for my english and not having a scanner (lol). I'm calculating the torque needed to rotate a wheel* around its own axis from above, ( see the link at the end of post). I have quite an good idea to how I'm supposed to calculate it but I feel that...

Homework Statement So we have a horizontal bar. Distance = r Forces = F All numbers remain constant with the exception of the distance, denoted as r(set)() Length of bar = 1m F1 = 10N r1-1 = 0m r2-1 = .25m (behind the point of rotation) F2 = 5N r1-2 = 0.5m...

Homework Statement A yo-yo has a moment of inertia of 75.0 g-cm2 about its rotation axis. What is the constant torque required to make it spin to 300 rev/min in one second, starting from rest? Homework Equations ∑ = Iα The Attempt at a Solution I was thinking since the question is asking for...

Homework Statement Consider the rigid body in the picture, rotating about a fixed axis z not passing through a principal axis of inertia, with an angular velocity \Omega that can vary in magnitude but not in direction. Find the angular momentum vector and its component parallel to z axis (...

Here is some background to the problem (in a stirred tank): "With yield stress non-Newtonian (viscoplastic) fluids, it is possible to generate an agitated volume around the impeller, defined as a cavern, surrounded by a stagnant region where the shear stress is insufficient to overcome the...

Consider the rotation of a rigid body about a fixed axis z, not passing through a principal axis of inertia of the body. The angular momentum \vec{L} has a parallel component to the z axis (called \vec{L_z}) and a component perpendicular to it (called \vec{L_n}). I have some doubts on...

Homework Statement Consider a block placed on a surface, in two different configuration, a and b. Explain the condition for which the mass is in equilibrium and describe qualitatively the rotation it follows when it falls. Homework Equations Center of mass theorem \sum F = M a_{cm} The...

Homework Statement [/B] Consider a barbell with two equal masses m that rotates around a vertical axis z not passing through its center with angular velocity \vec{\omega}. The barbell is forced to stay in this position by an appropriate support. Identify the forces exerting torques on the...

I have put together a tricycle, but it only allows for a 4in sprocket on the axel. I have added a motor to the tricycle and do not get enough torque. The motor came with a 6in sprocket, which will not fit on the axil. My idea is to set it up so the chain goes from the motor 1in to the 6in to...

I 'd like to clarify some doubts about the rotational motion around a fixed axis of a rigid body, in the case the angular momentum vector \vec {L} is not parallel to the angular velocity \vec {\omega} . In particular, consider a horizontal barbell with two equal masses m , forced to rotate...

Hi! I would like to apologize in advance, for my english. I am working on a gear reducer for a manual wheelchair, and are trying to figure out what kind of design I think would work. But as I am calculating there are a few (simple) things I could need some help with. As a test I've chosen a...

Can a scalar field exert a torque on a particle?

Homework Statement The figure shows a cylinder of mass 3.5kg, radius 4.4cm and length 10.2cm with 105turns of wire wrapped around it lengthwise, so that the plane of the wire loop contains the axis of the cylinder. What is the least current which while flowing through the loop will prevent the...

I am new here to the forum, so I hope I am posting in the right section. I am working on a school project, planning to design a robotic wing. I am first devising a way to use gears with a servo motor (Hitec MG995 - http://www.electronicoscaldas.com/datasheet/MG995_Tower-Pro.pdf) as the driver...

Homework Statement The torque ## \vec{τ} ## on a body about a given point is found to be equal to ## \vec{A} × \vec{L} ## where ##\vec{A}## is a constant vector, and ##\vec{L}## is the angular momentum of the body about that point. From this it follows: (Multiple answers correct) (A) ##...

Homework Statement Hi everybody! I know that is a classical problem, but I haven't been able to find an answer to my questions in the other threads so here we go: We have a yoyo made of 3 aluminium disks (density ρ). The two side disks have a radius R and thickness D, and the middle disk has...

Homework Statement A circle-formed circuit with an area A lies in the (xy)-plane. An electric current I runs clockwise through the circuit (figure 1). An external magnetic field B exerts a torque t = D(3i - 4j) on the circuit, where D is a positive constant, i is the x-axis unit vector and j is...

We have tried to convert a petrol engine into a compressed air engine back in our graduation project. At that time we only measured the RPM of engine using tachometer and pressure of compressed air using pressure gauge. Now, we need to know the power of wngine at those readings. As the setup is...

Homework Statement A metal rod of length 90cm has a disc of radius 24cm fixed rigidly at its centre(refer to picture attached). The assembly is pivoted at it's centre. Two forces, each of magnitude 30N, are applied normal to the rod at each end so as to produce a turning effect on rod. A rope...

I want to drive a trike but using dynamo at pedaling and the electrical power given to 400 watt motor So any suggestion what i can do best

Homework Statement At the instant illustrated, which best describes the angular momentum of the ball and net torque on the ball, as measured around the origin? L⃗ is in the kˆ direction, ⃗τ is 0. Homework Equations torque= (F)x(r) Tension in rope= (mv^2/r)+qvbThe Attempt at a Solution I am...

Homework Statement http://media.collegeboard.com/digitalServices/pdf/ap/apcentral/ap13_frq_physics_c_mechanics.pdf The problem is above. It is number 3. The solutions are below: http://media.collegeboard.com/digitalServices/pdf/ap/apcentral/ap13_physics_cm_scoring_guidelines.pdf Homework...

Hello! I took a quality certification test yesterday and there was a question on there about torque wrench formulas. I didn't have anything about that in my notes, so I took some time this morning to create a cheat sheet based on what I could find on the web. 1) In some of the forums, they...

Homework Statement Homework Equations ΣM=Στ The Attempt at a Solution I know how to get the net torque about point P, but I am having difficulty determining where the moment arms for each force should be. I did 9 simpler questions before this no problem, but this diagram is a bit more...

Homework Statement For my physics lab, they had us do a simple static equilibrium experiment where we rested a ruler on a fulcrum (at its center of mass) and then attached varying amounts of weight on either end at different distances from the fulcrum. This screenshot is the data we recorded...

Hi, I'm currently learning about moments and equilibriums. I'm able to solve the problems quite properly, like determining different forces, distances and etc. what intrigued me is that when we say that an object has a moment of 1700 Nm about point o. Does it mean that the object will provide...

Homework Statement say a fridge of width "w" and height "L" is being pushed on by a force F at an angle θ to the horizontal. This force is applied at a height of "h" above the ground. I want to know what the max value of h can be such that the fridge doesn't tip and the coefficient of...

1. Homework Statement A cylinder of mass M and radius R rolls (without slipping) down an inclined plane whose incline angle with the horizontal is theta. Determine the acceleration of the cylinder's center of mass and the minimum coefficient of friction that will allow the cylinder to roll...

Hey guys, I'm having difficulty with my university project which is to build an electric bike. My design is to have a friction wheel attached to the shaft of my 800W 2800rpm electric motor which is rated at 2.8Nm. I have two issues with my spreadsheets at the moment. Can someone please help...

I honestly don't know how to find the friction, much less frictional torque, when given things like this. 1. Homework Statement "If you lift the front wheel of a poorly maintained bicycle off the ground and then start it spinning at 0.72rev/s, friction in the bearings causes the wheel to stop...

The definition of torque is τ= r x F Let's consider a disk that is rotating around his axis of symmetry, we are usually used to calculate the torque applied by a tangential force at the disk using as r the radius of the disk, but can I define a torque of the force using as r the generic...

Imagine a motor, spinning a rotor blade around and around and around and around and around... How does the angular velocity of the rotor blade, and the torque affect the thrust produced?

Recently I have been researching torque and horsepower. I know that the lower the car gear, the more the torque. However, whenever I see specifications of a car, it says : X lb-ft of torque at Y rpm. Now, shouldn't they specify the gear that was measured in? Or is this the torque the engine...