Rigid body Definition and 335 Threads

Homework Statement The foot of a ladder rests against a wall,and its top is held by a horizontal tie rope. The ladder weighs 100 N and its center of gravity is 0.4 of its length from the foot. A 150 N child hangs from a rung that is 0.2 of the length from the top. Determine the tension in...

Homework Statement Im programming physics simulation. ...rigid body collision with ball. The ball is OK, but I have to push and rotate the rigid body. I have the contact point and the velocity(v) that I would add to the bodys current velocity if I wouldn't have to rotate it. So I need to...

Homework Statement There's a problem that I don't even know really where to start. It seems extremely complex to me. Basically there's a reverted cone of mass M with a mass of mass m that can slides over it without friction. But there's a constraint of motion for the particule, it must stay...

Homework Statement Pin C joins members ABC and CDE Homework Equations Sum of moments at a point = 0 Sum of vertical forces = 0 Sum of horizontal forces = 0 Weight of triangle acts as a force at its centroid (1/3) its length according to this figure. The Attempt at a Solution...

Rigid body -badly worded problem :( - Homework Statement Consider a symmetric trompo in a uniform gravitational field, with its inferior point fixed. a)Write down the Lagrangian. Determine the conserved quantities and from them study the motion of the body. b)Determine the stability...

Sorry in advance if this is a ridiculous question, but I've always wondered about this. Let's say we could create a wire in space away from any gravitational affects. Make the wire 2 light seconds long, for example. If we pulled on one end, when would the effects be felt on the other end? I'm...

Homework Statement A rigid body is rotating with angular velocity 2 rad/s about an axis in the direction of the vector (i + j + k) and passing through the point Q = (0, 1, -1) on the body. Find the linear velocity of the point P = (1, 0, 1) on the body. (You may use the result v = ω x...

Simple rigid body collision reaction (Newton III) Hi everyone! I'm writing a physics engine as part of a game I'm making. Up until this point I've implemented inter object collisions in a rather quick and dirty manner. Whenever something moves into something else, it is simply teleported back...

a force is applied at a arbitrary point in a rigid body. Does another force equal to it and parallel to it applied to it another point produce the same effect?

Homework Statement I want to analyse two colliding balls, rolling flat on a billiard table. I have recorded two collisions from above the table. A 1D collision and a 2D collision. In both collisions only 1 of the balls are rolling before the collision. Known is: mass of the balls: m1=207g...

Homework Statement A system is made of the following things: A homogeneous disk of mass m = 4kg. Having radius r = 80cm's. A point P (m = 2kg) free to rotate around a horizontal axis which is perpendicular to the disk in point A. AO = OP/2 If the system starts from rest and AP forms a...

Hi i want to know what the difference between general plane motion and rotation about fixed axis is? im using their formulas for work and energy study and as far as i see their general equations are the same. how do i identify which is which. also in a disk with planar motion, is the...

Homework Statement I'm trying to include rigid body rotation in a problem I'm working on but can't seem to figure it out. Two shafts oriented vertically are connected by a thin cross member of length R. Holding one shaft stationary and applying a constant tangential load F to the other...

Say I have an odd shaped rigid body in pure rotation. I fix an orthogonal x-y-z coordinate system to the body, and coincide the origin of this coordinate system to the origin of my global coordinate system X-Y-Z. I have 3 Eulerian angles (as functions of time) which I can use to describe the...

Homework Statement The boom in the figure below weighs 2600 N and is attached to a frictionless pivot at its lower end. It is not uniform; the distance of its center of gravity from the pivot is 35.0 % of its length. Homework Equations Find the tension in the guy wire. Find the...

Homework Statement An object with a mass of m = 5.4 kg is attached to the free end of a light string wrapped around a reel of radius R = 0.265 m and mass of M = 3.00 kg. The reel is a solid disk, free to rotate in a vertical plane about the horizontal axis passing through its center as shown...

Homework Statement The two blocks in the figure are connected by a massless rope that passes over a pulley. The pulley is 14cm in diameter and has a mass of 2.4 kg. As the pulley turns, friction at the axle exerts a torque of magnitude 0.54 Nm . Homework Equations so m1 = 4.0kg m2= 2.0 kg M...

Homework Statement Two forces P and Q are applied as shown to the corners A and B of a square plate. Determine their magnitudes P and Q and the angle (weird B) knowing that their resultant R has a magnitude R = 120 N and a line of action passing through O and forming an angle of 30 degeres...

Hi, first sorry for my bad English, I am more skilled to read than to write in English I don't know if this is the right section for this topic. The problem is described in the title of the topic. My guess is that each of the two wheels goes on with circular trajectory around a same...

Assume a stick of length 15*3*10^8 metre. One end points towards me, at the other end we place a ball very near to the end of the stick. If i push the end pointing towards me with some force, instantaneously the ball will be moved(~). At the same time, a light beam emanating...

Homework Statement Due to an increase in power, the motor M rotates the shaft A with an angular acceleration(α=0.06θ^2) rad/s^2, where θ is in radians. If the shaft is initially turning at ω =50 rad/s, determine the angular velocity of gear B after the shaft undergoes an angular displacement...

Homework Statement A turntable rotates at a uniform angular speed of 3.0 rads^-1. A record is dropped from rest onto the turntable. Initially the record skids on the turntable but eventually rotates together withe the turntable. (a) While the record is skidding on the turntable, the angular...

hi I have multiple torques acting at different points on a rigid body I want to find the resultant force and torque (about the body CM) I think I can see how to "convert" an off-center torque to a torque + translation using the parallel axis theorem - but am wondering if there is a...

I am and have been trying to do a specific simulation for the last several weeks. It seems like I take one step forward two steps back. See below: See the attached files. I'm on Ansys Workbench 13. [PLAIN]www.plastics-consulting.com/rod.stp[/URL]...

Homework Statement I think the problem was taken out from Landau&Lifgarbagez's book on classical mechanics. An inhomogeneous cylinder of radius R rolls over a plane. The mass is distributed in such a way that a principal axis is parallel to the rotational axis of the cylinder and the center of...

Homework Statement Find acceleration-x ̈ of the load. Force F=10G, friction μ=1/3, mass of he body is G. I tried two ways of solving this problem but not sure if any is good. I think second is good. But wondering if first is also good? Homework Equations Ek=1/2 G/g x ̇^2 Fμ=G μ The...

Homework Statement Using the corresponding constraints conditions, calculate the kinetic energy of 1)A homogeneous cylinder of radius a that rolls inside a cylindrical surface of radius R>a.Homework Equations My toughts: I hope they meants "roll without slipping". Let's consider this case...

Homework Statement Determine the principal moments of inertia of a circular cylinder with radius R and height h. Homework Equations Not sure. The Attempt at a Solution This is the first problem of this kind I attempt to solve. From what I've read on wikipedia, the tensor of...

pls see attached file for the question. so W = change in T + change in Ve + change in g T = 1/2 mv2 + 1/2 I (w1^2 - w2^2), but how do u find the velocity, shouldn't it be 0 since it starts/stops at v=0. for Ve = 1/2 kx2, how do u know how far it stretches once the moment is applied? :O :(...

hey guys, please see the attachment for the question. i drew FBDs and everything. i want to know a few things tho. how do i calculate the tension in the pulley? if they'd given me acceleration i could have used T-mg =ma. but they havent. also once the Tension is found, do i just find the...

I know and understand why the c of m of a uniform hemispherical shell (i.e a hollow hemisphere) is r/2 on the axis of symmetry (where r=radius of shell). I looked at the solution of the following question and still don't understand. Question: A hemispherical bowl, which may be modeled as a...

Homework Statement A pendulum consists of a light rigid rod of length 250mm, with two identical uniform solid spheres of radius 50mm attached one on either side of its lower end. Find the period of small oscillations (a) perpendicular to the line of centers, and (b) along it.Homework Equations...

If a rigid body has a net moment e.g. rotating clockwise at 2Nm moment about the centre of mass, does every point on the body have 2Nm moment? Or just the point at the centre of mass have a net moment? Thanks

I need some help with the equation of moments for this exercise: Each wheel of an automobile has a mass of 22 kg, a diameter of 575 mm, and a radius of gyration of 225 mm. The automobile travels around an unbanked curve of radius 150 m at a speed of 95 km/h. Knowing that the transverse distance...

Homework Statement This is a very simple problem to state, yet I've not found any answers on PF or anywhere else online. So let's say we have a simple rigid body like a rod. We apply an external force Fext for a fixed time dt to the rod in two different ways: (1) directly on the center of...

1. A uniform thin rod of weight W is supported horizontally by two vertical props at its ends. At t=0 one of these supports is kicked out. Find the force on the other support immediately thereafter - it should be in terms of W. 2. Homework Equations : I=M(L^2)/12 3. Don't even...

Homework Statement The bicyclist applies brakes as he descends a track making an angle β with a horizontal direction. The front wheel of the bike locks and starts to slip along the incline. Find the magnitude of the decleration a that would cause a dangerous condition of tipping about the...

Right, I need to find out the Radius of gyration of an object as it rolls down a ramp... So I've got the equation K=r square root((g.t^2 sin theta/ 2x) -1)) These are the numbers I have... Object A R = 0.004 g = 9.81 t = 16.45 theta = 5.31 x = 0.66 I got an answer of...

Hi, everyone. I'm required to complete an open ended analysis of the following problem: http://imagefrog.net/show.php/146581_image.png http://imagefrog.net/show.php/146581_image.png I'm not requesting a solution, I'm only looking for assistance in relation to determining the spring stiffness...

Homework Statement A uniform rod of mass M and length l is hinged at point O as shown in fig. A small particle of mass M/3 strikes the rod with velocity v at a distance 3l/4 from O and sticks to it. Find the value of v such that the force exerted by the hinge on the rod just after the impact...

Homework Statement hello, I need help with projection of a rigid body with moment of inertia I, the rigid body was earlier moving on a circle of R radius with \omega angular velocity and was making angle of \alpha when centripetal force stopped to work. And I need to know if this rigid body...

Homework Statement Hi there, I'm starting with rigid body, and I'm having some trouble with it, so I'll need your help :D I have this exercise now, but I will probably come with some others later. The exercise says: The collars A and C glide along the vertical rods and B of the horizontal. If...

Note this is physics I This should be the right section as this is not homework.. Ok I'm having trouble understanding the concepts of rolling without friction, kinetic energy linear and kinetic energy rotational. I have a hard time following my professor in class and usually like to go...

Hi, here's the question: A massless, rigid rod has motors attached on each end. The motors are each connected to a massive disc, and the motors accelerate the discs in the directions indicated by the arrows. Due to the torque from the each motor on its disc and hence that on the rod and...

Hello, I have a question regarding how I'm simulating motion using the common time integrating approach to simulating rigid bodies. I have net forces and solve for position from those: acceleration = force / mass velocity = initial velocity + acceleration * time position = initial position...

Homework Statement So rigid body (ring, cylinder, sphere), who's radius of gyration is known, rolls down an inclined plane without slipping. Find velocity as a function of height. m - mass of the body. y0 - initial height, g - gravitational acceleration, v - speed. I - moment of inertia, K -...

I have been given the following problems for practice for an upcoming test that is going to have similar problems on it. I was wondering if someone knows how to do them as I want to make sure that I know how to do them correctly so I will be prepared come test time. Thank you!

Homework Statement The rigid body assembly is made from a 15 Kg disk, an 8 Kg slender rod, and a small 4 Kg sphere. The radius of the disk is R = 0.4 m and the length of the rod is L = 1.2 m. The pivot O is at the center of the disk. The assembly is released from rest at the horizontal...

It is a known fact that every rigid body has a set of orthogonal axes called principle axes about which when rotated the angular momentum vector and the angular velocity vector point in the same direction. Inside the body we can take any point as the origin and find a combination such that the...

Rigid Body Momentum? Homework Statement **** PICTURED IS ATTACHED *** The center of the homogeneous disk of mass m shown below has an initial velocity of v0 up the slope. Find the velocity of the disk after an elapsed time of !t, assuming that the disk rolls without slip. Use...