Disk Definition and 783 Threads

Any help would be great Show that the centre of the mass of a uniform circular disk of radius, R, is at a point (4/3pi)R from the centre of the circle.

I am interested in conducting an experiment to prove or disprove the unusual qualities cited by many concerning the Faraday Disk generator. I have read from several different sources (some bias and others non bias) that an induced EMF can be measured while rotating an induction disk inside...

I already posted this somewhere, but silly me, i can't find it. Q: A disk of radius 2.40 cm and mass 1 kg is pulled by a string wrapped around its circumference with a constant force of 0.36 Newtons. What is the angular velocity of the disk to three decimal places after it has been turned...

Q: A disk of radius 2.40 cm and mass 1 kg is pulled by a string wrapped around its circumference with a constant force of 0.36 Newtons. What is the angular velocity of the disk to three decimal places after it has been turned through 0.85 of a revolution? So I started by obtaining my degrees...

So I've been using: \alpha=\tau/I More specifically: \alpha=(r*F)/(.5mr^2) I know I'm getting the acceleration just fine. I've then been using: \omega^2 = 2\alpha\Delta\Theta I know the problem is coming in here. Probably in conversion of units (rad/s^2) to (rev/s^2) or something...

My problem: A grindstone in the shape of a solid disk with diameter=0.480m and a mass of m=50.0kg is rotating at omega = 820rev/min. You press an ax against the rim with a normal force of F=190N View Figure , and the grindstone comes to rest in 8.00s. I need to find the coefficient of...

A computer disk is 8.0cm in diameter. a refrence dot on the edge of the disk is initially located at theta= 45 degrees. The disk accelerates steadily for 1/2 second, reaching 2000 rpm, then coasts at steady angular velocity for 1/2 second. what is the speed of the refrence dot at 1...

I'm curious, when am I supposed to use Washer, Shell or Disk method when trying to answer questions involving integrals and volume? Is there something specific I should look out for? I just can't tell the difference. Any help is appreciated. Thanks.

A disk of radius 1.4 cm has a surface charge density of 4.9 µC/m2 on its upper face. What is the magnitude of the electric field produced by the disk at a point on its central axis at distance z = 12 cm from the disk? I tried solving this problem in the same way you would solve a similar...

I have a diagram for this at http://snipurl.com/diagr There is a uniform disk with radius R, mass M, it has a string wrapped around it and is attached to a fixed rod. Part 1: Show the tension in the string is 1/3 the weight of the disk what i have done for this is Torque=Fd and...

hi, a friend is heading over to malaysia in the next few days and asked me if i wanted a 10000rpm ( 8mb cache, SATA ) 74 GB WESTERN DIGITAL 10000RPM hard disk. i would say yes but i am not sure if it will work on my pc my motherboard is an ASUS P4P800SE with Intel 865PE Chipset can someone...

Let me first start by saying that this problem is a challenge problem and the due date has passed (friday). I've still been working on it because it stumped me. in my physics class we did some integration based inertia problems. my calculus isn't all that great so its a bit tough for me...

/k. A disk of mass 15 kg and radius 25 cm is rotating initially at 20 rad/s. A constant force of 40 N is applied tangentially to it's edge, positively accelerating the disk. a) At t= 5 seconds, calculate the- 1) rotational velocity of the disk 2) the instantaneous power supplied to...

A uniform disk of mass Mdisk = 4.4 kg and radius R = 0.28 m has a small block of mass mblock = 2.4 kg on its rim. It rotates about an axis a distance d = 0.18 m from its center intersecting the disk along the radius on which the block is situated...

A disk 8.0 cm in diameter is initially at rest. A small dot is painted on the edge of the disk. The disk accelerates at 600rad/s^2 for .5s, then coasts at a steady angular velocity for another .5s. What is the speed of the dot at t = 1 s? Through how many revolutions has it turned? I...

Okay, so I'm having problems figuring out how exactly i can map the interior of Cassini's oval (|z^2-a^2|<r^2 , 0<a<r) onto the unit disk (|w|<1), so that the axis of symmetry are preserved. Anyone know how to do this? :confused: (In this case, the cassini oval is a peanut shaped domain, i think)

A .22kg , .22-m-diameter plastic disk is spun on an axle through its center by an electric motor. What torque must the motor supply to take the disk from 0 to 1500 rpm in 5.00 ? I used the equations T(thau)=alpha/I w_f=w_i + alpha*(t_f - t_i) I found I to be equal to .021kgm^2 then...

Hello. Could anyone give me a hint in this problem? There´s a disk (mass m ad radius a) rotating with angular velocity w0 (only rotation). If this disk is translating in xy plane, parallel with the y-axis with its center aligned at x0, how ca I describe the angular momentum L (t), and it´s...

I'm having some trouble with a conceptual problem. Your help or input would be greatly appreciated. Here's the problem. A disk and a hoop, both having the same mass, are rolled down a hill. The disk rolls faster than the hoop. Why is this so? Thank you for your time!

I have a little problem. There is this message I get, after I direct connect to someone on AIM that says, "The disk in drive A: needs to be reformatted." The options are "Ok" or "Cancel". I clicked "Ok" and the harddrive makes a buzzing sound for quite a while. Why and how do I fix this?

When two pads squeeze a moving rotor with thousands of pounds of force in a disk brake, the friction resists the rotation of the disk enough to slow a car. How much resistance (if any) does the squeezing of the pads provide if you try to pull the moving rotor out at roughly 90 degrees...

I’ve been working on some electroGrav theories and am now wanting to start building models to try and test these theories. I’ve a 8ft satellite dish that I was thinking on using as a mold, but have no good ideas on how to go about this. As like a “UFO”, I need to create a top and bottom...

i am trying to create an animation simulating a coin spinning/rolling on a table top. how can the phyics involved over time be explained in an equation? any references (especially illustrated ones) would be helpful. thanks in advance!

My friend who is working in Seagate told me, the plant is now rolling out high production of 200~400GB HDD. The 40 and 80 GB HDD will phase out soon. Therefore, we will soon see a price drop in HDD. Wait a little bit and you will get higher capacity with cheaper price. :smile:

hoop and disk rolling(help please) ok I've been looking at this forever and can't get it...dont know what to do..i would appreciate it if someone could help -------------------------------------------------------------------------- A uniform solid disk and a uniform hoop are placed side...

if a disk which is initially spinning with an angular velocity,w, radians per second is pushed with an initial linear velocity of v, what is the resultant motion? assume a kinetic friction of mu normal to the disk i would love to see how this problem is solved. it seems real...

I'm not quite getting the following problem: A thin disk of dielectric material, having a total charge +Q uniformly distributed over its surface, and having radius a, rotates n times per second about an axis through the center of the disk and perpendicular to the disk. Show that the...

I've included a picture. A uniform disk of mass Mdisk = 5 kg and radius R = 0.2 m has a small block of mass mblock = 2.5 kg on its rim. It rotates about an axis a distance d = 0.17 m from its center intersecting the disk along the radius on which the block is situated...

Hello , Is there any way to get run knoppix from the Hard disk and make it one of the Operating systems to choose ? I hope someone helps me :D

40GB? 60GB? 80GB? Bull****t! I long time ago had found that the hard drive i bought contains less space that what it claims. look at this: Are we cheated by the manufacturers?

http://www.mercola.com/2003/feb/22/petabyte.htm that's 1 million gigabytes, or 1,000 terabytes. Good lord what will we do with it? Ya I can picture going for a walk and listening to my MP3 player with- every song ever written in the palm of my hand. the 24 million texts in the library of...

I am studying for our final, and there is this problem that is confusing me. There are three disks, with transmission axis of the 1st being 10 deg. from the vertical, the 2nd at an angle theta from the vertical, and the 3rd at an angle 120 deg from the vertical. Unpolarized light, I(0) is...

Here's the problem and I'm close to the answer, but I guess close isn't good enough on a Physics exam. A spinning solid disk, rotating with angular velocity Wo, is put down on a level surface. It slides and rolls until it reaches an angular velocity W at which it rolls without sliding. Show...