Torque and rotation Definition and 66 Threads

< Mentor Note -- thread moved to HH from the technical forums to use a scpecific schoolwork problem to illustrate the general concept of torque in a FBD > I'm writing up a lab report for Physics class and I have to draw FBDs for torque being applied to a ruler resting on a pivot point. I've...

This isn't a real homework problem (i.e. I made this problem up myself for my own purposes), but I figured this is the correct forum to post. 1. Homework Statement In the following figure we have two rods connected to each other, and the bottom rod is connected to the blue structure (G), and G...

Homework Statement Determine the moment of inertia of a rigid body on the picture: The radius of the inner cylinder is R and the outer is 2R. Homework Equations 3. The Attempt at a Solution [/B] I thought of subtracting the big cylinder inertia from the small and adding the hanging body and...

why force parallel to the axis of rotation do not make any torque.

Homework Statement [/B] A thin, uniform, 3.8kg bar, 80cm long has two 2.5 kg balls glued on at either end. It is supported horizontally by a thin, horizontal, frictionless axle passing through its centers and perpendicular to the bar. Suddenly the right hand ball becomes detached and falls off...

The situation is part of a mechanism I have been working on. It is used for a bicycle to automatically store and release energy with a spring. It is somewhat similar to a car clutch. Homework Statement Two friction discs are rotating with different angular velocities and different torques. The...

I am looking to find the max force on a single rototiller blade. The blade is being rotated at 180 RPM with 60Hp. The blade is bolted to a Flange that is welded to center shaft. The shaft has a 3.5" diameter. The diameter of the cutting circle is 24". The blade is a 10.25"x3"x.25" rectangle. If...

Homework Statement A uniform thin stick of mass M and length L has a moment of inertia about its centre of mass of I = (1/12)ML^2. The stick, which is pivoted at one end, is held horizontal and then released. Assuming the pivot is frictionless, calculate: i) the linear acceleration of the free...

Homework Statement To derive Potential Energy for dipole p in Electric Field E. 2. Homework Equations Potential Energy is the work done by the external agent in turning the angle of the dipole from the U=0 position to another position against the influence of the electric field applied...

I have a question on finding the inertia of a rod with a pivot point somewhere along it's length. So the inertia of a rod is IStick cm = 1/12 *m*L2 Does L2 = (2L/3)2 = 4L2/9 -> 1/12 *m*[4L2/9] or is it something like m*L2/12 + m* (2L/3)2? If it's the second one then may I ask why it's that...

Firstly, let me explain that I am mostly inept at mathematics. Piecing together the required information is becoming a real challenge because of that. I am motorizing a dobsonian telescope. I have read many accounts of success and the steps involved. The places where detail is commonly left out...

Prior to my life as a database administrator I was a hi lead logger in coastal British Columbia, which involves harvesting logs with machines capable of putting huge strain on cable and hydraulic systems. What got me to thinking this was a friend just let me know someone we know was recently...

Homework Statement http://i.imgur.com/7ZRsVj5.png Homework Equations I can't apply correct method ! The Attempt at a Solution In bigger figure, i cut into 8 equal parts.So , total moment of inertia=8 I But it's wrong ! I know it's wrong because i can't able to find angle between any two...

Hi I'm looking for some info and advice. I've looked across the Internet and forums looking at different formulas for working out the torque requirements for a motor but can't find anything that helps me. I have designed a small amusement ride. Please see pic below. The outer ring...

Homework Statement The following problem is part of a physics lab with unclear directions. The lab prompt says: Find the angular acceleration of a meterstick as it slips down a wall. Here is my interpretation of the lab: A meterstick of mass 0.15kg is leaning against the wall. At an angle of...

Hello all. I am working on a project and am a little lost on the physics end. Basically, I have 6 circular platforms that need to be rotated in the same direction. I figured I would have a gear under each and a chain connecting them similar to a bicycle chain. I need to figure out what DC...