Disc Definition and 374 Threads

Hello, I have a circular pipe where there is an inbuild pressure and I have kept a circular weight on it. I would like to know what would be the lift of the weight under certain pressure. I know the relation that the minimum weight required to keep the pipe closed is F = P*A. (this F will be...

Writing force equations for block ##m## : $$T-mr\omega^2=m\ddot{r}$$ and for block ##M## : $$Mg-T=M\ddot{r}$$ I think there are mistakes in my equations as they are leading to nowhere and morever i think force methods are really risky in this regard . It would be better to write the total energy...

Using these equations, I find L=0.02Nms, I=0.02Kgm^2 and KE=10mJ However, i don't think that this is the right method here.

Hey folks, I've been looking around but can't piece this together as there are more than one equation and variable to take into account. My situation - I have a pmma material disc on an axis , the center hole (axis hole) is 20mm wide so a radius of 10mm, while the outer edge is at a radius of...

Hello to all, I wish to detect the hit of a airsoft pellet on a shot plate with an ESP32 board. to do this I have basically two options: Either, detect the signal as digital (hit / missed) or detect the signal as analog signal with a piezo disks. The analog signal will have more information...

The hint says the following: "Since the cords are inextensible, every particle of a cord must be in circular motion about the point where it is affixed to the ceiling. Therefore, the velocities of the points where the cords are leaving the disc are perpendicular to the string" Due to the fact...

Summary:: Conditions inside a protoplanetary disc. I have just finished writing a fictional story that takes place inside a protoplanetary disc. Now I think I should determine how realistic it is. My question -- Somewhere in a typical PP disc, the gas pressure would be in the range of one...

Hello to everyone, first of all shame on me I has to ask and can not figure out it by myself... The problem is I am trying to code game where two homogenous discs with same mass and same diameter, no fricition due to gravitational forces, can collide. I can figure out the speed and direction...

I started out by drawing a diagram: So I thought I would try torque with the axis of rotation in the center: ##T_1R = \frac{Mr^2}{2}\alpha## and given that ##T_1## is equal to ##F## in the positive direction. ##\alpha = 266.6 \frac{rad}{s^2}## Then knowing the relationship between angular...

To find the initial potential energy of the system we can assume the disc to be placed inside a hollow sphere of the same radius and ##\sigma##, the potential energy inside a charged hollow shell is: $$V = \frac{\sigma(4\pi R^2)}{4\pi \epsilon_0 R} = \frac{\sigma R}{\epsilon_0}$$ the potential...

Summary:: Could there be a place in a newly forming protoplanetary disc where the gas pressure and temperature would be anywhere close to survivable? I am writing a fiction story that takes place there, and I want to know how far from reality this premise would be. When a protoplanetary disc...

A disc of radius ##a## has a smaller disc of radius ##a/2## removed. The resulting object has mass ##m##: The centre of mass ##G## is a distance ##h = \dfrac{\pi a^3 - \dfrac{3\pi a^3}{8} }{\dfrac{3\pi a^2}{4}} = \dfrac{5a}{6}## from the edge. The moment of inertia of the shape about the...

A disc initially has angular velocities as shown It's angular momentum along the y-axis initially is ##L_s## I tried to find its angular momentum and ended up with this:##L=I_{x} \omega_{x}+I_{y} w_{y}+I_{z} z_{z}##The z component of angular momentum is thus ##L_{z}=I_{z} \omega_{z}## However...

I've a disc which can rotate freely about two perpendicular axis (fixed to the body) If I simultaneous try to rotate it about the two axis, what will happen?

I know there are more convenient differential elements that can be chosen to compute the moment of inertia of a disc(like rings). the mass of the differential element: $$dm = (M/\pi R^2) (dA) = (M/ \pi R^2) (2\sqrt{R^2 - y^2})(dy)$$ the moment of inertia of a rod through its COM is...

Someone that I tutor asked a simple but pretty good question today which I thought I'd share the answer to. In a tidied up form: a disc with centre at the origin and central axis parallel to a unit vector ##\mathbf{n}## in the ##xy## plane rotates with a constant angular velocity...

Torque appiled by smaller disc = mga emf of disc due to B = Bwr2/2 Current I = Bwr2/2R force = IBr = Bwr3/2r torque = rF = Bwr4/2r mga = Bwr4/2r

Consider the system of the mass and uniform disc. Since no external forces act on the system, the angular momentum will be conserved. For elastic collision, the kinetic energy of the system stays constant.Measuring angular momentum from the hinge: ##\vec L_i = Rmv_0 \space\hat i + I \omega_0...

I've tried to explicitly solve the Fourier's equation in cylindrical coordinates but I'm getting some messy integrals which cannot be solved analytically. Additionally my instructor said that there's a neat trick for this problem and it's possible to obtain the answer in a rather elementary...

The area of a circular disc with radius ##r## is ##A=\pi r^2\;\mbox{cm}^2##. A smith must make a circular metal disc of ##400\pi\;\mbox{cm}^2## with an accuracy of ##\pm{5}\;\mbox{cm}^2##. Which accuracy range must have a ##20\;\mbox{cm}## disc? Answer The metal worker wants to obtain ##|\pi...

I was first wondering wether we can solve this question by applying conservation or energy or not but after googling it I found that we can't apply conservation of energy since there will be some energy lost in this case. I don't know how this energy is getting lost. My second doubt was if we...

From a freebody analysis I got, $$ \vec{r} \times \vec{F} = |r| |F| \sin( 90 - \theta) = (R-r) mg \cos \theta$$ and, this is equal to $$ I \alpha_1$$ where the alpha_1 is the angular acceleration of center of mass of small circle around big one, $$ I \alpha = (R-r) mg \cos \theta$$ Now...

"A smooth horizontal disc rotates with a constant angular velocity ω about a stationary vertical axis passing through its centre, the point O. At a moment t=0 a disc is set in motion from that point with velocity v0. Find the angular momentum M(t) of the disc relative to the point O in the...

I would like to know what is the current consensus on the effect of the position of the wing relative to a tractive propeller disc's uniformity of thrust (the focus configuration would be WWII fighters).

A penny of mass 3.10 g rests on a small 20.0-g block supported by a spinning disk. The block is sitting at the edge of the disc at a radius of 12 cm. If the coefficient of friction between block and disk are 0.750 (static) and 0.640 (kinetic) while those for the penny and block are 0.450...

I know that there is a known equation to calculate the magnetic field strength of a rotating disc which I have made use of in here Do you agree that revs per minute of the disc turns out to be 9337 rpm? Thanks for any help! Much appreciated

I thought that there was a standard placement for disc brake calipers on the front and back wheel assemblies for high-performance sports cars. I thought that I usually saw them placed at the back of the front wheels and the front of the rear wheels, but lately I've seen the opposite and other...

Why is the gravitational potential energy of the chain's center of mass equal to the total kinetic energy of the disc after it was fully wrapped? My first thought was to write ##E_{0}=(M/2+M)g∗2πR=E_{f}= Ep## (from the chain) ##+Ec## (from the disc). Instead he wrote ## mg \frac{l}{2} ## = ##...

Well, I tried plugging the data in the formula. I know that ##\vec a_b = 0; \vec \omega=3 rad/s ; \vec r## can be calculated using trigonometry. Then I also know that ##v_{relx}= 10 cm/s##, ##a_{relx}=15 cm/s^2##, ##\vec {\dot{\omega}}=-10 rad/s^2##. But how do I get ##v_{rely}## and...

The first doubt that comes to my mind is "I have to determine the acceleration with respect to what?", because the problem doesn't tell. Then, I have some problems when having to plug the data in the formula of acceleration. ##\vec a_B=0## because the origin isn't accelerated, ##\vec{\dot...

I had a KNOPPIX 5.0 disc. I made a copy of the files on this disc, but I then damaged the disc. I have tried simply burning these files onto a dvd disc but it won't boot. Can I use the files that I saved to created a "bootable" KNOPPIX disc?

I have a disc. The center of the disc is its center of mass and the motion of the disc is purely rotational (no translation). What is the angular velocity in the center of the rotating disc?

There are two points of the smaller disck such that a line is tangent to the two discks and passes by that point. If the particle leaves of any point belongin to the arch that connects these two points, then it will hit the other disck. So I managed to calculate the value of this arch and divide...

Please see attached illustration (from Discover September 2004. Einstein 100 years special issue). Is it correct that one key to Einstein's thinking is to analyze a spnning disk. That "Since the rim of the disk travels faster than the center of the disk, the theory of relativity states that the...

Double integration maybe?? I calculated potential due to shell on plate's center but not on other points on it's surface.

I am attempting to build a sodium iodide detector on MCNP. I am using a disc source and I have been trying to define it in terms of a cell that I placed underneath the detector. When I run it, I get 0's for my counts. This indicates to me that my source isn't hitting my detector. I keep...

I am doing a project, but am struggling to find relationships of proportionality or formulae between my dependent variables (angular velocity, displacement, acceleration of the disc and kinetic energy of the system) and my independent variables (falling masses and then the number of winds) or...

Homework Statement A disc of radius R rolls without slipping along the parabola y= ax2. Obtain the constrain equation Homework Equations Because there's no slipping, then: ##R d \theta = ds (1)## Where ##\theta ## is the angle between the line from the center of the disc to a fixed point...

So the kinematics of the contact point of a disc rolling without slip in a Cartesian plane if fairly straightforward. The velocity for the contact point is just v = ω r ev where r is the wheel radius and ev the current direction vector of the wheel. However, say that you grab the plate and...

Homework Statement Hi I am looking at this derivation of differential equation satisfied by ##\phi(z)##. To start with, I know that such a disc ##D## described in the derivation can always be found because earlier in the lecture notes we proved that their exists an ##inf=min \omega ## for...

Homework Statement I understand that if the change in impulse is 0.25, that because disc B is originally stationary the momentum disc B will have is equal to the impulse. My question is how do we do this in terms of change in momentum? Homework Equations ΔP = Pf - Pi P = mv The Attempt at a...

I have a disc that is rotating due to air being blown at its outer radius. The incoming relative velocity of the air is high, therefore the effect of friction supersedes the effect of conservation of angular momentum. The tangential portion of this velocity decreases due to the friction as it...

Homework Statement A force of magnitude 50N is applied at the bottom point Q of a disk of radius 8m that is pinned at P (leftŸmost point) See attached picture (a) Find the angle between the force and the vector from P to Q. (b) Find the magnitude of the applied torque. Homework Equations...

Pick a random set of N points from the unit disc. Calculate the distance between all pairs of points and call the smallest value r. Do this calculation for many such sets. Please give me a hint how to estimate what the average value of r is. I guess a computer program could quickly come up with...

Homework Statement [/B] A thin cylindrical rod with the length of L = 24.0 cm and the mass m = 1.20 kg has a cylindrical disc attached to the other end as shown by the figure. The cylindrical disc has the radius R = 8.00 cm and the mass M 2.00 kg. The arrangement is originally straight up...

A disc and a hoop (ring) both of same mass and radius roll down an inclined plane of height "h". It is well known the disc has great velocity than that of the hoop at the bottom. I am fixed in the situation after they start rolling horizontally. Which will go farther? If the surface is...

I want to solve the following problem: Suppose B=B(0,R) be a ball in C^n, n>1. Let f be holomorphic in B and continuous on B closure. If f(a)=0 for some a in B, show that there is p in boundary of B such that f(p)=0. I assumed f(p) is non zero for every point p in boundary B and create...

Homework Statement I have a disc with radius R. One half has the charge density of +2σ and the other half has −σ. The task is to find the total charge of the disc. Homework Equations dQ=ρ2πr^2 I would use this equation if the charge density was uniform The Attempt at a Solution My first idea...

Hi, I've seen many videos of neodymium magnets sliding slowly down an inclined copper plate, or slowly down a copper tube - due to eddy current braking,but never the other way around. My question is; will a copper disc sliding down an inclined magnetic plate, or down a magnetic tube act in the...

before I ask anything I know this has been probably talked about a lot in the past from various different angles, yet when I am searching for answers I cannot find a satisfactory answer that would look at it from the perspective I wish so here is my try. I've talked with a mentor of mine about...