Rotational mechanics Definition and 78 Threads

Rotational mechanics... Homework Statement This is actually a simple harmonic motion question but the doubt i have is with a concept in rotation... I will state the exact problem... A solid sphere(radius R) rolls without slipping in a cylindrical trough(Radius 5R). Find the time period of...

Two boys are sliding towards each other on a frictionless, ice-covered parking lot. Jacob, mass 45kg, is sliding towards the right at 8m/s and Ethan, mass 31kg, is sliding towards the left at 11m/s along the same line. When they meet, they grab each other and hang on. (a) What is their velocity...

Homework Statement The figure shows two cylinders of radius r1 and r2 rotating about their axes (along the length) with speeds \omega_1 and \omega_2 The two cylinders are moved closer to touch each other keeping the axes parallel. The cylinders first slip over each other at the point of...

Homework Statement The figure shows two cylinders rotating about their axes, all the variables involved are shown. The two cylinders are moved closer to touch each other keeping the axes parallel. The cylinders first slip over each other at the point of contact but slipping finally ceases due...

Homework Statement For my physics class we need to research on internet how torque and rotational mechanics has to do with planes. I already know a little about torque. I know that torque helps planes turn and spin (pivot). Is there anything else torque has to do with planes? Also, could...

Homework Statement Cliff and Will are carrying a uniform 2.0 m board of mass 71 kg. Will is supporting the board at the end while Cliff is 0.6 m from the other end as shown. Cliff has attached his lunch to the end of the board, and the tension in the string supporting the lunch is 200 N...

Homework Statement A block hangs by a massless string that is wound around a solid cylindrical pulley of radius 0.20m. The pulley is free to rotate on frictionless bearings about an axis through its center. The block is released from rest. The pulley completes 3 rotations in 4 seconds. A)...

Homework Statement If a CD makes 1500 revolutions in 5 minutes, what is the CD's average rotational speed (in units of rad/s)Homework Equations \omega = \frac{\Delta\theta}{\Delta t} -or- \omega = \frac{2\pi}{\Delta t}The Attempt at a Solution This problem seems a little too simple (and I...

Homework Statement I am studying for a final exam and I do not know how to solve this problem: A 10 kg mass hangs by a rope of negligible mass. The upper end of the rope is attached to and is wound around the other edge of a solid uniform wheel which is free to rotate on a horizontal...

A motor rotating at 60rpm comes to rest in 10 revolutions with its angular velocity decreasing linearly with angular displacement.Determine it angular velocity as a function of time and determine angular velocity w at t=3 sec.. I need help with this problem...Please someone help...I can't...

hi, a doubt regarding rolling motion of a ball down the incline has been giving me sleepless nights for a couple of days now, here is it- if a perfect sphere is placed on an inclined plane with angle of inclination x (say), its translation of the CM, and rotation can be treated seperately...

Hi, I'm actually working on a problem in Rotational mechanics. I'll just hint the problem. In a rotating body,tangential acc=(radius)angular acceleration. velocity=(radius)angular velocity.thus, [tangential acc/angular acceleration] =[velocity/angular velocity] can we use the...

I've just got some small problems this time. The first being,do the particles at the axis of a rotating body really stand still??Don't they spin about themselves??

Hi, I've been doing rotational mechanics at school and at the end of the chapter,the parallel and perpendicular axis theorems appear to have sprung out of nowhere! The proofs are given in the book but somehow, they don't make any sense. I can't understand their implications in the real...

Hi, I've done rotational mechanics at school and there are certain things that really feel strange about it. In Physics everything has a reason. So I want to find out the reasons to certain things. firstly-we started off rotational mechanics by talking about angular displacement,angular...

A rod standing on frictionless table(Rotation) Homework Statement A rod of length l is standing on a friction less surface. A slight impulse is given to the rod and hence the rod starts falling. Find the torque,angular acceleration ,angular velocity, the normal force by the ground and the...

Please note, this is a series of problems, with a series of answers. I believe that I understand how to do the problems, but for some reason, my answer is wrong, and I can think of no reason why. Homework Statement Problem 1: http://img355.imageshack.us/my.php?image=physics1jw9.png i) I...

Homework Statement Q] A meter stick weighing 240 grams is pivoted at it's upper end in such a way that it can freely rotate through this end. A particle of mass 100 gms is attached to the upper end of the stick to a string of length 1m. Initially the rod is kept vertical and the string...

Can somebody explain to me clearly what is MOMENT OF INERTIA, what is TORQUE, what is ANGULAR MOMENTUM. If you ever comparing those with linear motion quantities, then please explain a little in detail what is the similarity between moment of inertia and mass, as I'm not getting it. Also, I...

Hello, Hopefully this is in the correct place. I am presented with a the following problem. "A hamster running on an exercise wheel, exterts a torque on the wheel. If the wheel has an angular velocity that can be expressed as: \omega(t)= 3.0 rads/s + (8.0 rad/s^{}2)t + (1.5...

Homework Statement A space station shaped like a giant wheel has a radius of 90 m and a moment of inertia of 4.50 108 kg·m2. A crew of 150 are living on the rim, and the station's rotation causes the crew to experience an acceleration of 1g (Fig. P10.47). When 100 people move to the center of...

please help me in solving ratational mechanics :rolleyes:. i am not able to understand where to apply moment of interia or torque acting on the body?:confused: i am a dropper & rotational is very important from iit(competitive exam) view. pleasez help:frown

Homework Statement A flywheel is a homogeneous cylinder of mass M with a hole in the middle where the axle connects with it. The outer radius of the wheel is R. The radius of the axle is r, and the mass of the axle is m. A weight of mass m_w is suspended from a string wound around the axle...

Homework Statement Problem: "A cylindrical 4.91 pulley with a radius of 0.338 m is used to lower a 3.80 kg bucket into a well. The bucket starts from rest and falls for 4.06 s. The acceleration of gravity is 9.81 m/s². What is the linear acceleration of the falling bucket? Answer in units...

Homework Statement A 0.4m diameter, 50KG, solid pulley wheel is used to derive a conveyor belt system on a production line. The belt is very light and it's mass can be taken as zero. The pulley wheel is accelerated from rest at 2 rads/s^2 for 3 secs, then rotated at a constant velocity for a...

Alright here's a problem that seemed pretty easy, but I'm really worried i over-simplified (which i often have a problem of doing) since the question was rated one of the harder ones... 1) A 2000-kg block is lifted at constant speed (v = .08 m/s) by a steel cable pasing over a massless pulley...

Hey ! Please help me out with this problem. A hollow sphere of mass m is released from top on an inclined plane of inclination [tex]\theta[\tex]. (a) What should be the minimum coefficient of friction between the sphere and the plane to prevent skidding? I did this...

I have a physics lab to do. Now, I want to make sure that I am on the right track (I don't want to go completely in the wrong direction). Essentially what we have for our lab is two cans of soup (both with the same dimensions and similar mass) which we roll down a ramp and let it roll until it...