Disk Definition and 783 Threads

Homework Statement Imagine a frictionless pulley (a solid cylinder) of unknown mass M and radius r = 0.200 m which is used to draw water from a well. A bucket of mass m = 1.50 kg is attached to a massless cord wrapped around the pulley. The bucket starts from rest at the top of the well and...

Homework Statement A uniform disk of mass M and radius a can roll along a rough horizontal rail. A particle of mass m is suspended from the center C of the disk by a light inextensible string b. The whole system moves in a vertical plane through a rail. Take as generalized coordinates x...

Homework Statement A uniform disk of mass Mdisk = 4.1 kg and radius R = 0.3 m has a small block of mass mblock = 2.9 kg on its rim. It rotates about an axis a distance d = 0.16 m from its center intersecting the disk along the radius on which the block is situated. a) What is the moment of...

Homework Statement A disk with a diameter of 0.07 m is spinning about an axle perpendicular to the disk and running through its center. a) How many revolutions per second would it have to rotate in order that the acceleration of the outer edge of the disk be 14 g's (i.e., 14 times the...

Disk method question Use the disk method to find the volume of the solid obtained by rotating the region bounded by y=x^2 and y=x about the line y=x.

I currently have an iso of a program inwhich I would like to install on my home desktop. However my home desktop only has a cd-rom drive and not a dvd room drive so I can't burn it to the disk. I know I can still mount and run it using a program such as daemontools however I don't know of a way...

I've attached a .pdf with the problem explanation, questions, and answers. I can't figure out for the life of me how to get these answers though. I've setup a countless number of integrals and can't seem to get it right. Any help you guys can give me would be greatly appreciated. *EDIT* Not...

How many zeros inside the unit disk does the following function have? f(z) = 3 z^621 - e^z. (in words, three times z to the power 621 minus e^z :) ...argument principle answers this question, but I have a problem evaluating the integral of f'(z)/f(z).

Can the surface of a hemisphere be distinguished from a disk without introducing a metric? What is the minimum amount of info we need to know to identify one space as a disk and the other as the surface of hemisphere? Both can have the same coordinate chart. For example, distance from...

Homework Statement y=\sqrt{x}, x=4, y=0 Homework Equations \pi\int^{c}_{d}{R(y)}^{2}dy The Attempt at a Solution I solve for x then pluged it into the formula \int^{2}_{0}{(y^{2})^{2}} The answer I got was \frac{32\pi}{5} but my textbook says the answer should be...

Homework Statement A circular plastic disk with radius R = 1.80 cm has a uniformly distributed charge of Q = + 2.15 106 e on one face. A circular ring of width 30 µm is centered on that face, with the center of the ring at radius r = 0.50 cm. What charge is contained within the width of the...

Homework Statement Suppose you design an apparatus in which a uniformly charged disk of radius R is to produce an electric field. The field magnitude is most important along the central perpendicular axis of the disk, at a point P at distance 2.60R from the disk. Cost analysis suggests that...

disk on a plank -- HELP! Homework Statement a disk of mass M is sitting on a plank of length l and mass m. a constant force F is pulling the plank to the right. assuming no slipping what are the accelerations? how far to the right will the coin move before reaching the left end of the...

A circular disk of radius r is used in an evaporator and is rotated in a vertical plane. It is to be partially submerged in the liquid so as to maximize the exposed wetted area of the disk. show that the center of the disk should be positioned at height r/sqrt(1+pi^2) ok i absolutely know how...

A uniform disk is lying on a flat, frictionless surface, and a force is applied as shown: http://www.freeimagehosting.net/uploads/ae622047b5.jpg What will be the motion of the disk.. more importantly, the motion of center of mass of the disk. will it move in a straight line, or will it move...

Hi, How do integrate this? I wish to see it step by step and I'm glad for any help i can get. \int_{ \vec{r}\in{A}} \frac{ \vec{v}+ \vec{\omega}\times\vec{r}}{| \vec{v}+ \vec{\omega}\times\vec{r}|}d^{2}r where A is area of disk with radius R.

Homework Statement A string is wrapped around a uniform disk of mass M = 2.5 kg and radius R = 0.05 m. (Recall that the moment of inertia of a uniform disk is (1/2)MR2.) Attached to the disk are four low-mass rods of radius b = 0.09 m, each with a small mass m = 0.7 kg at the end. The device...

Homework Statement A uniform disk (like a record turntable) turns with a frequency of 5.2 rev/s around a frictionless spindle. A non-rotating rod of the same mass as the disk and length equal to the disk's diameter is placed on the freely spinning disk so both turn around the spindle. (Idisk...

Homework Statement A uniform disk is set into rotation with an initial angular speed about its axis through its center. While still rotating at this speed, the disk is placed in contact with a horizontal surface and released. What is the angular speed of the disk once pure rolling takes place...

Homework Statement A 250 g , 20.0-cm-diameter plastic disk is spun on an axle through its center by an electric motor. Homework Equations What torque must the motor supply to take the disk from 0 to 2000 rpm in 4.50 s? The Attempt at a Solution I know that Torque = Inertia times angular...

Comments ---------- hey, I am trying to figure out the moment of inertia with respect to various axis. I am, having trouble figuring out how to find out dm. I know that dm = (rho)*t*dA, but i am having trouble figuring out the t*dA part. i tried using t*dA = (pi)(r^2)/2 That didn't...

Homework Statement I'm wondering how to write the equation of constraint for a solid disk (mass m, radius R) that is attached to a spring (spring constant k) and rolls without slipping. Any suggestions? Homework Equations there are no equations to use, but this has to do with lagrange's...

Hey guys! I'm doing my B.S thesis (Mech. Eng.) and I've come across the problem of a rolling disk with friction. Imagine a disk in real world rolling on a flat surface with no external force or torque applied to it except for the interaction of the surface (Normal, friction, etc.). Now...

A potter has a stone disk of radius 0.483 m and mass 101 kg rotating at 71.9 rev/min. The potter stops the wheel in 6.54 seconds by applying a wet towel against the rim with a radially inward force of 103 N. Find the effective coefficient of kinetic friction between the whell and the wet towel...

Volumes: The Disk Method [Resolved] 1. If the area bounded by the parabola y = H - (H/R^{2})x^{2} and the x-axis is revolved about the y-axis, the resulting bullet-shaped solid is a segment of a paraboloid of revolition with height H and radius of base R. Show its volume is half the volume of...

Homework Statement A flat, uniform, disk, of radius 1.5 m and mass 10 kg, is rolling on its edge with a translational velocity of 12 m/s. What is the kinetic energy of the disk? Homework Equations not sure which one but I'm guessing it's one of these two: K = .5(I)(w)^2 K =...

Homework Statement It's part of Kleppner and Kolenkow 7.4. See the attached picture. (The disk is rotating around the vertical "stick", not rotating towards it. (I have bad drawing skills) The question mainly asks what is the normal force on the disk. I am stuck trying to find the moment of...

Along the axis of a uniformly charged disk, at a point 0.6 m from the center of the disk, the potential is 91.4 V and the magnitude of the electric field is 86.5 V/m; at a distance of 1.5 m, the potential is 46.8 V and the magnitude of the electric field is 27.0 V/m. Find the total charge...

Homework Statement A disk has mass 3kg and outer radius 50 cm with a radial mass distribution (which may not be uniform) so that its moment of inertia is (2/7)mR^2. The disk is given a hard kick (impulse) along a horizontal surface at time t0. The kicking force acts along a horizontal line...

Homework Statement A solid uniform disk of mass 21.0 kg and radius 85.0 cm is at rest flat on a frictionless surface. A string is wrapped around the rim of the disk and a constant force of 35.0 N is applied to the string. The string does not slip on the rim. How much string has unwrapped from...

Homework Statement A disk with a mass of 4kg and a .20m radius is free to rotate about a horizontal axis. A 4.0kg mass and a 8.0kg mass are attached by a massless string, which is hung over the disk. If the string does not slip, what is the angular velocity of the disk after 2 seconds...

1.Provide the question and knowns A uniform disk turns at 3.7rev/s around a frictionless spindle. A nonrotating rod, of the same mass as the disk and length equal to the disk's diameter, is dropped onto the freely spinning disk. they then turn together around the spindle with their centers...

In future HDD will be replaced by solid state disk,SSD will become the mainstream. Solid State Disk （SSD）： it is a general definition to distinguish traditional mechanical drives which depends on complex mechanical parts and control circuits, bascially any drive with electronics storage media...

Homework Statement Find the electric field due to a Charged Disk at a distance of "d" which is in the disk's axis direction. The charge has it's maximum value at disk's center and decreases towards the edges. I have the solution for uniformly charged disk but I can't figured it out for the...

Homework Statement A computer hard disk starts from rest, then speeds up with an angular acceleration of 198 rad/s2 until it reaches its final angular speed of 7683 rpm. How many revolutions has the disk made 10.7 s after it starts up? Homework Equations t=wf/a delta0=wi*t+(1/2)(a)t^2...

Homework Statement What is the rotational inertia of a solid iron disk of mass 46 kg, with a thickness of 6.31 cm and radius of 19.4 cm, about an axis through its center and perpendicular to it? Homework Equations either 1/2MR^(2) or I = sigma (1->N) Mi x Ri^(2) The Attempt at a...

Homework Statement (Actually, this is not a homework, but a project I'm trying to accomplish but I have almost forgotten physics...) There is a disk weighting 100kg with a radius of 0.6 meters. What would be the torque needed to accelerate the disk from 0 rpm to 6 rpm in 10 seconds...

Hello, I have a problem about my disk driver: My CD disk driver doesn't appear in the "my computer" window. when i noted that error, I checked in driver manager but it didn't show any error. Then i got an idea to restart the computer and the disk driver appeared for a short time and...

Homework Statement Here's the problem statement, uploaded onto google docs: http://docs.google.com/View?docid=d277r7r_48f97jqsgs Homework Equations The Attempt at a Solution i) L=r*p L=R*m*v I think that's the answer, b/c they don't give us any constants to work with, but...

Can someone explain to me when you should user the Shell / Disk / Washer methods? I don't understand how to determine which method to use.

Spinning Disk problem. Due tomorrow! Help please! A disk with a diameter of 0.1 m is spinning about an axle perpendicular to the disk and running through its center. a) How many revolutions per second would it have to rotate in order that the acceleration of the outer edge of the disk be 14...

Reducing it to three questions, because I'm pretty confident on the others. 9. Find the volume of the solid generated by revolving about the line x = -1, the region bounded by the curves y = -x^2 + 4x - 3 and y = 0. --- I graphed everything, and then translated the graph 1 to the right making it...

Last few I can't seem to do, but on the others, can someone check my answers?. The last few I need help getting through. 1. Find the volume of the solid formed when the region bounded by the curves y = x^3 + 1, x = 1 and y = 0 is rotated about the x-axis. My answer: int(pi(x^3+1)^2,x,-1,1)...

Homework Statement A manufacturer drills a hole through the center of a metal sphere of radius 5 inches. The hole has a radius of 3 inches. What is the volume of the resulting metal ring? Solution: You can imagine the ring to be generated by a segment of the circle who equation is x^2...

Hi, I know the following calculation is incorrect but have been unable to find the error. The calculation is to integrate I = \int z^2 \sqrt{r^2-z^2}dz. Trying u-substitution: u = \sqrt{r^2 - z^2} z^2 = r^2 - u^2 2z dz = - 2udu dz = \frac{-udu}{z} =...

I understand the answer to this part of the problem intuitively but there's definitely something in the math that I'm missing-- Homework Statement Along the axis through the center of a charged disk, for a point P at a distance x from the center, the potential will be...

Homework Statement Okay, I totally do not understand how to derive the electric field made by a dipole or a line or a ring or etc. Homework Equations When finding the electric field, when you make an estimate, saying that the test charge is very far away, it should be similar to kQ/r^2...

Homework Statement A solid uniform disk of radius 0.250 m and mass 55.0 kg rolls down an incline that makes an angle of 15 degrees with the horizontal. The disk starts from rest from the top of the ramp. Find the speed of the disk's center of mass when it reaches the bottom of the ramp(linear...

Deleting a file that "can not read from the source file or disk" I downloaded a torrent file the other day and half way through the download i decided i didn't want to finish downloading so i deleted the file using a command prompt on bittorrent. Now the file (which is on my desktop) is deleted...

Hi, Homework Statement The electric field of a uniform charged disk at a point on its axis at a distance x from the disk is given by E = 2k_e\pi\sigma(1-\frac{x}{\sqrt{x^2+R^2}}) where R the radius of the disk and \sigma the surface charge density. In my notes it says that when x\gg R, that is...