Rigid body Definition and 335 Threads

Homework Statement Pretty picture: I am currently stuck on #1. Homework Equations Not exactly sure but... For #1, I assume the relevant equations are those relating the (i) gravitational force to momentum and (ii)torque due to gravity to angular momentum: (i) F = dP/dt (ii) K = dM/dt...

Homework Statement A sphere of mass M and radius R it`s given a velocity Vo on the base of a inclined plane (theta being the angle) and friction coefficient mu (you may assume that static and kinetic friction are equal) Find the position of the ball as a function of time Homework...

Homework Statement Three belts move over two pulleys without slipping in the speed reduction system. Point A on the input belt moves to the right with a constant spped of 0.6m/s. Determin the velocity of point C on the output belt, and the acceleration of point B on the output pulley...

Homework Statement An elevator system in a tall building consists of a 710 kg car and a 810 kg counterweight, joined by a cable that passes over a pulley of mass 280 kg. The pulley, called a sheave, is a solid cylinder of radius 0.700 m turning on a horizontal axle. The cable has comparatively...

Homework Statement A uniform rectangular tile drops without spinning until its corners reach positions (0; 0; 0); (2a; 0; 0); (2a; 2b; 0); (0; 2b; 0), when it strikes the top of a vertical pole at a point very close to the (0; 0; 0) corner. Just before impact the velocity of the tile was...

hi, when will i use 0.5mv^2 and when will i use 0.5Iw^2 when will i use both? as far as i can see one represents the movement of the center of mass and the other the angular movement. so as far as i understand for a moving cylinder i would use the sum of those. but i can't think of any...

hi, i am trying to solve this question. A thin stick of mass M = 4.9 kg and length L = 2.6 m is hinged at the top. A piece of clay, mass m = 1.0 kg and velocity V = 4.9 m/s hits the stick a distance x = 2.20 m from the hinge and sticks to it. What is the angular velocity of the stick...

My teacher ask us to do a research on physics. I have been choose a topic of torque. I need to find a problem statement before i can start my research. My problem is i have no idea on problem statement. Can somebody help me? ASAP!

hi, i'll be glad to get some help with that. thanks A thin uniform rod has mass M = 0.5 kg and length L= 0.55 m. It has a pivot at one end and is at rest on a compressed spring as shown in (A) in the attached image. The rod is released from an angle θ1= 63.0o, and moves through its...

Homework Statement http://img340.imageshack.us/img340/7379/87835960.png r_{i}=.3 m \text{ and } r_{o}=.9 m The spool has a weight of 300N and a radius of gyration k_{O} = .45 m. A cord is wrapped around its inner hub and the end subjected to a horizontal force P = 50N. Determine the spool's...

Can anyone recommend a textbook or web paper that proves that, in general, a free rigid body will act in the following way when the body is subjected to a force (or impulse) that is torque producing: a) The center of mass (CM) moves in a straight line. b) The body rotates about an axis through...

Homework Statement A very light, rigid rod with a length of 0.570 m extends straight out from one end of a meter stick. The stick is suspended from a pivot at the far end of the rod and is set into oscillation. Determine the period of oscillation. Homework Equations omega =...

Let me start by saying thank you to any responses I receive. I understand the methods for solving this problem but I have concluded that either part or all of my solution is incorrect. After solving for the angular velocity, I differentiated my answer in order to check the angular...

Hi, I have a question regarding Equilibrium problems. Here is the example of my hw. Find the tension T in each cable and the magnitude and direction of the force exerted on the strut by the pivot. I know how to find T. The only problem is i couldn't imagine the force exerted on the strut by the...

I try to clearify it as much as I can, and I greatly appreciate the given answers. Suppose that we have a rigid body. We attach a movable coodinate frame on this body. Normally, if I perform 3 successive rotations such as Z-Y-X or Z-Y-Z (or any other 24) I can describe its rotation in...

Homework Statement The small end rollers of the 3.6 kg uniform slender bar are constrained to move in the slow, which lies in a vertical plane. A the instant theta=30 the angular velocity of the bar is 2 d/sunter-clockwise. Determne the angular acceleration of the bar,k the reaction at A and...

Homework Statement Homework Equations \SigmaM = I\alpha \SigmaF = ma The Attempt at a Solution I have made an attempt at this problem, it can be seen in the image below. I think I have done everything correctly, but my answer is incorrect. Any help would be greatly appreciated.

Homework Statement A whimsical piece of furniture has the base shaped like a star. Formulate the condition in terms of the location of the center of mass of the object that the piece would not topple over. A sketch would be helpful. The Attempt at a Solution Can someone help me...

how are weights distributed on a beam

Homework Statement Consider a gymnast on a bean placed on upright posts. The beam has a mass of 10kg and the gymnast has a mass of 50kg. The beam is 5 meters long, and the gymnast is 1 meter from the right side. The gymnast may be treated as a particle. Find the force exerted by each...

There is a rod treating as rigid body, the rod which mass is m and lenghth is R rotate about one end of itself with the angular acceleration \alpha . Apply a tangential external force f on another end to make the rod rotate. Now divide the rod into elements of mass. For each mass element dm with...

This isn't homework, it's for a simple computer program I'm trying to write. It's been a long time since I took a physics class, but I seem to remember getting homework questions like this. http://www.imagechicken.com/uploads/1244655138002459200.png If I have a 2D rigid body, I know its...

Hi guys, I'm going to university this fall and am preparing this summer for the physics courses I will be taking. I have Kleppner and Kolenkow's mechanics book, and things were going smoothly until I hit the problems in chapter 7 on rigid body motion in three dimensions. In this chapter, topics...

We all learn in the introductory mechanics class that the motion of a rigid body can be composed of a rotation and a translation. But how can one prove this? I mean: Let us have some rigid body in two configurations in space, how can I show that I can transform one configuration to another by...

I'm currently programming a 2D rigid body dynamics engine. While I have realistic collision detection and response between polygons, I have trouble in the simulation once I implement gravity. When these rigid bodies are influenced by gravity, they never fall to complete rest (e.g. they...

I have uploaded the question with solution at this address: http://i41.tinypic.com/o5xm5j.jpg All I need to know is why in the moment equation "NA*a - F*b = 0" the forces Nb and Nc aren't included. Is it because the moment is being calculated about the dot in the middle, and the other two...

1. A solid sphere has a radius of 0.200 m and a mass of 150 kg. How much work is required to get the sphere rolling with an angular speed of 50.0 rad/s on a horizontal surface? Assume the sphere starts from rest and rolls without slipping 2. The attempt at a solution I found V first. V= rw =...

here is the question and how i tried to solve it http://img242.imageshack.us/img242/7320/83882436ug7.th.gif

Hi PF, I'm a bit disappointed because the final exam is coming up next Monday and I can't solve this problem. Not that I don't know how to proceed, but I just get a wrong answer. Homework Statement See figure to imagine the situation. This is about a wheel of radius R which contains a circle...

I have no idea what the solution to this problem is and would appreciate if someone pointed me in the right direction.

Homework Statement imagine a thin length of wood supported by two supports, one at either end. One support dissapears and the other turns into a pivot (as gravity acts on the wood). Show that the load supported by the pivot is Mg/4. The Attempt at a Solution i don't know where to...

Homework Statement Hello, I've tried all I could and get very confused about how to approach the problem. Here it comes : A disk of mass M and radius R can rotates around an axis passing by the point A without friction situated on its circumference. The disk is in a vertical plane. We let...

a plank is conected horizontally at both ends to two points. One of the points dissapears and the other turns into a pivot. show that the Planck of length l,mass m pivoted at one end has an acceleration (3/2)*g initially i used parallel axis theorm do derive the moment of inertia of a...

When considering pure rotation of a rigid body about some point , then can we always consider the body to be concentrated in its centre of mass and use all force related equation treating it like a point object situated at it center of mass.? Why? Can anyone prove mathematically because there...

Homework Statement A piece of cloth with irrelavent mass is wrapped around a 67.5 kg cylinder of radius 0.167 m. Joe holds the free end of the cloth. The cylinder is released from rest, and Joe pulls the tape upward at a speed that just prevents the center of mass of the cylinder from falling...

A 0.15 meter long, 0.15 kg thin rigid rod has a small 0.22 kg mass stuck on one of its ends and a small 0.080 kg mass stuck on the other end. The rod rotates at 1.7 rad/s through its physical center without friction. What is the magnitude of the angular momentum of the system taking the center...

Homework Statement The pirate is walking the plank. If the plank weighs 500 N and the weight acts at the centre of the plank, how far (distance x) can our pirate, who weighs 780 N, walk before the plank tips and he falls. All dimensions are in meters. ANS: 0.769 m (Look at picture)...

Hello, I am new here, so I don't know if this is the right place to post this question or not, if not please move it to the right place. At the moment I am working on making a computer simulator for rigid bodies using java, the only problem is that I thought that high school physics would...

Homework Statement Determine the reactions at the base of the light pole shown in fig.1 Homework Equations Summation of force and moment of a system in equilibrium is 0. The Attempt at a Solution The resultant force of due to the weight of the light pole and lamp is 185g N...

Hi! I have been working on a rigid body subject quite a long. But till now there is an unresolved question for me. When we calculating the torque acting on the rigid body we use the following definition of the torque: t = r X f, X - is a cross product. So if I calculate the torque in a...

Hi, I am new to these forums so i hope I am putting this in the right place... I am completely lost with how to even start a simple box on plane physics simulation. I've read dozens of formulas and tutorials, I understand them mostly but they all seem very abstract in the sense of how to use...

1. Problem I need to find the principal moments of inertia about the center of mass of a flat rigid 45 degree right triangle with uniform mass density. 2. Useful Formulae I_{xx}=\int_{V} \rho (r^{2}-x^{2}) dV I_{jk}=\int_{V} \rho (r^{2} \delta_{jk} - x_{j} x_{k}) dV 3. Attempt at a...

Hi, I'm attempting to do a simulation of rigid bodies dynamics, and have ran into a problem. Homework Statement It can and at some point will occur that multiple forces will be acting on a rigid body, at different points with different strength and under different angles. Obviously...

I am just playing around with physics simulation in c++... and my latest obsession is simulating rigid body motion (specifically rotation) with no external torque, for now. The equations of motion in question are the 'Euler equations' which relate the angular acceleration (omega-dot) around any...

The solid uniform disk of radius b shown can turn freely on an axle through its center. A hole of diameter D is drilled through the disk; its center is a distance r from the axle. The weight of the material drilled out is Fwh. Find the weight of an object hung from a string wound on the disk...

Homework Statement A rigid body consists of three thin uniform rods, each of mass m and length 2a, held mutually perpendicular at their midpoints. Show that the moment of inertia is the same for any axis passing through the origin. Homework Equations The Attempt at a Solution I...

Homework Statement prove that when the net force on a rigid body is zero, the torque about any line perpendicular to the plane of the forces is equal. Homework Equations \tau=I\alpha The Attempt at a Solution it is known that angular velocity, and hence angular acceleration about...

Homework Statement The illustrated equilateral triangle is supported by two links. d = 0.5 m. At the illustrated position,\dot{\theta}= 9 rad/s and \ddot{\theta}= 0 rad/s^2. Find the magnitude of a_C. http://img406.imageshack.us/img406/7264/tonguech66315yx0.th.gif The Attempt at a...

Homework Statement thin uniform metal rod is bent into three perpendicular segments, two of which have length L . You want to determine what the length of the third segment should be so that the unit will hang with two segments horizontal when it is supported by a hook u <--hook...

Homework Statement A 392-N wheel comes off a moving truck and rolls without slipping along a highway. At the bottom of a hill it is rotating at 25.0 rad/s. The radius of the wheel is 0.600 m and its moment of inertia about its rotation axis is 0.800MR^2. Friction does work on the wheel as it...