Circular Definition and 999 Threads

√Homework Statement Show that the gravitational field due to thin uniform circular plate of radius a at point distant R from center and on the axis passing through the center and perpendicular to the plane of the plate is given by E= -2πGρ[1-R/(a^2+R^2)^1/2] Homework Equations F= GMm/r^2...

Uniform circular motion requires a force perpendicular to the velocity. Therefore, the work done by such a force is zero because the dot product of the force and the path is zero. So there is no energy gain beyond the kinetic energy arising from its constant speed. But if I have a mass (rocket...

Hi, Could you explain the reason why the velocity varies in the wake region behind the cylinder in "flow over a circular cylinder"? the velocity variation is, minimum at a point parallel to the centre point of the cylinder and increases to free stream velocity as the vertical distance increases...

Homework Statement A circular coil with center on the z axis and orthogonal to the xy axis carries a current. The coil is in a magnetic field B with axial symmetry compared to the x axis. B forms an angle θ with the z axis. Calculate the magnetic force acting on the coil. 2. Homework...

Homework Statement object of mass 0.20 kg tied to a string is made to move in a vertical circle. When the object is at the highest point, the tension in the string is zero. Determine the tension in the string when the object is at the lowest point. [11.8 N] Homework EquationsThe Attempt at a...

Hi all, I had a question that I can't seem to find an answer too. I was hoping people could point me in the right direction, or let me know if there is an "easy" method. It has to do with the classic example of two stones in water producing constructive and destructive interference...

Homework Statement For low-speed(laminar) , steady flow through a circular pipe, the velocity u varies with radius and takes what form? Please see this link for picture of the pipe...

Homework Statement A .8 kg lead ball is whirled on the end of a string 5 meters long. When the ball passes through point A at the top of the path, the tension in the string is 4.96 N. What is the speed of the bob at point A? *NOTE - POINT A is at the top of the circle... Homework Equations...

Homework Statement Bob starts at rest from the top of a frictionless ramp. At the bottom of the ramp, he enters a frictionless circular loop. The total mass of the child and the cart he sits in his m. What must the height of the ramp be in order for the cart to successfully traverse the loop...

1. A conducting loop is shrinking in a constant ##\vec{B}##-field that is perpendicular to the loop-axis. The radius of the loop is given by ##r(t)=r_{0}e^{-at}##. The resistance in the loop is ##R(t)=2 \pi \rho r(t)##. What force is needed to keep the loop shrinking like this?2. Faraday's law...

Homework Statement In a classical model of a multi-electron atom, electrons are assumed to move in a modified electrostatic potential $V(r)$, given by; $$V(r)=\dfrac{-k}{r}e^{-r/a}$$ Show that the effective potential is ; $$V_e(r)=\dfrac{J^2}{2mr^2}+\dfrac{-k}{r}e^{-r/a}$$ Then show that...

Homework Statement When you are spinning an object in a circular path, you are applying centripetal force towards the center of the circle while the velocity vector is perpendicular to it. Therefore the Force component affecting the velocity is FCos(90) = 0. Keeping this in mind, how can you...

My book says that for uniform rotational flow, the velocity at any point is proportional to r (v = wr.) In vortex flow, the velocity at any point is proportional to 1/r (angular momentum is conserved.) However, in uniform rotational flow, isn't angular momentum also conserved so the same logic...

Homework Statement A 1 kg ball with a radius of 20 cm rolls down a 5 m high inclined plane. Its speed at the bottom is 8 m/s. How many revolutions per second is the ball making when at the bottom of the plane? Homework Equations circumference = 2πr velocity = distance / time = circumference /...

Homework Statement A spaceship in outerspace has a donut shaped with a 500 m outer radius. The inhabitants stand with their heads towards the center and their feet on an outside rim. Over what time interval with the spaceship have to complete one rotation on its axis to make a bathroom scale...

This is the equation for the cone A \sqrt{x^2 + y^2} The double integral \iint A \sqrt{x^2 + y^2} \space dy \space dx \space \space \space\text {From x= -1 to 1 and y=} -\sqrt{1-x^2} \space to \space \sqrt{1-x^2} \text{ is very difficult to evaluate. I've tried polar coordinate substitution...

I don't understand, how can tidal forces make the orbits more circular? Perhaps it has something to do with the fact that in elliptical orbits (unlike in circular orbits) the velocity is not always perpendicular to the acceleration? Or maybe it does not have to do with the tidal forces from the...

I am working on a system that uses circular motion of 65° of a circle with 8,5cm radius. Thing is, What first comes to mind are Linear guides with a curved/circular track and I've found some examples such as; http://ind-techno.com.ua/en/cat/20/556/78030/...

Homework Statement A 3.75 kg bucket pile of water is swung in a vertical circle. If the speed of the bucket at the top of the loop is 6.20 m/s, then the radius of the largest circle through which this pail could move without the water leaving the bottom of the pail would be what? m = 3.75 kg...

Homework Statement A hypothetical magnetic field existing in a region is given by ##\vec{B}=B_o\vec{e}_r##, where ##\vec{e}_r## denotes the unit vector along the radial direction. A circular loop of radius a, carrying a current ##i##, is placed with its plane parallel to the X-Y plane and the...

6 people are invited to a dinner party and they are sitting on a round table. Each person is sitting on a chair there are exactly 6 chairs. So each person has exactly two neighboring chairs, one on the left and the other on the right. The host decides to shuffle the sitting arrangements. A...

I might be going crazy or searching at the wrong places. Is there an empirical formula for solving the hydrodynamic entry length of laminar flow through a circular annulus? Thanks!

Hey, I'm an adult who finally realized that physics is great and tries to recall (or rather learn for the first time) what he learned at the school. I've been reading some basic things around. It's not really a homework question, I'm just trying to understand the laws here. 1. I know that if a...

Could someone explain to me how the kinetic energy of a body moving in a circle is like? I got tempted it stays constant as the speed is constant but that turned out to be false. I am interested in places where the body is at top, side and bottom and so on. So I'd like to also know what the KE...

Homework Statement [/B] You are given a particle, with the trajectory of a circle, with radius of 3 meters. The particle moves clock-wise, and when t=0, the x, y coordinates are (0, -3). Find parametric equations for the coordinates (x, y) in terms of the parametric t (time). Homework...

Homework Statement So a body $m$ is on a uniform circular motion ($\omega = d\theta/dt = \text{constant}$), it is suspended by an inextensible rope with negligeable mass Homework Equations P = mg , didnt know what to put here The Attempt at a Solution So this is what the book did. What I...

Homework Statement There is a tether ball swinging around in a uniform circle on a rope that is 1.90m long. Marcus hit the ball so hard that the string holding the ball made a 20.0 degree angle to the horizontal. What is the tension in the rope if the ball has a mass of 1.40 kg? Assume that the...

Homework Statement A bucket of water (10kg) is swung vertically. Radius is 1 m. It takes 1 second to spin the bucket in a full circle. a. How much force has to be exerted at the top of its motion? b. How much force must be exerted at the bottom? Homework Equations vtop=sqrt(gr) top: Ftension=...

A 400kg roller coaster cart travels along the inside of a vertical circular track of radius 10 m. At its highest point it moves at 20 m/s. Friction between the cart and track is negligible. Find the cart's speed one quarter of a loop later (when it's at the same height as the loop's center). I...

Homework Statement Homework Equations Centripetal Acceleration = v2/r Fnet = ΣF The Attempt at a Solution The block exerts a force W equal to its weight on the box at the top most position. This upward W minus W downwards and an unknown F downwards equals a net Fc downwards. So F equals Fc...

[Note by mentor: This thread does not use the homework template because it was moved here from a non-homework forum.] Hello, I have a problem with this exercise. I don't know if my solution is right! Could you check it, please? A proton with kinetic energy Kp is moving in a uniform magnetic...

The position function for a particle moving on a circle (with constant speed) is: ## \vec{r}(t)=\left \langle r\,sin(t), \, r\,cos(t) \right \rangle ## Taking the first and second derivatives, ## \vec{v}(t)=\left \langle -r\,cos(t), \, r\,sin(t) \right \rangle ## ## \vec{a}(t)=\left \langle...

Homework Statement A block of mass M is on a frictionless table that has a hole a distance S from the block. The block is attached to a massless string that goes through the hole. A force F is applied to the string and the block is given an angular velocity w0 , with the hole as the origin, so...

Hi, I am trying to solve one problem of circular motion and I searched on Internet and found many things and I am confused about different forces or I think same force is shown as different symbol. What I learned is as follows:Force = F = ma (horizontal movement - where height is not involved)...

Relative equations: F = ma a = v^2/r Fcent = mv^2/r ωf^2 – ωi^2 = 2αs s = θr ω = v/r Problem statement and work so far are all included: (I am having trouble with 5 and no clue how to start on 7-9) You are designing a roadway for a local business, to include a circular exit ramp from the...

Homework Statement The problem is: An amusement park is replacing it's stand-up roller coaster with a G-Force ride. Riders will enter the ride at the apex and lean against the wall of the ride. The G-force ride will speed up until riders reach height h above the apex. Determine the minimum...

Homework Statement https://www.dropbox.com/s/slpu1p8jplmxzmy/Screenshot%202014-11-18%2020.11.58.png?dl=0 Homework Equations Fnet = ma ma = (mv^2)/r The Attempt at a Solution ai) Ft up, mg down /\Ft I m I \/mg aii) both down m I I \/mg \/Ft aiii) Ft right, mg down m - >Ft I \/mg b)...

Hello, Given an electromagnetic wave that is, from a classical point-of-view, not circular polarized. Does that correspond in QM to photons with the ZERO spin eigenstate? Thanks in advance.

Homework Statement [/B] A circular table of radius rotates about its center with an angular velocity 'w'. The surface of the table is smooth. A groove is dug along the surface of the table at a distance 'd' from the centre of the table till the circumference. A particle is kept at the starting...

Homework Statement A particle is traveling on a circle with a radius R. The particle's radial acceleration is given as: a_r=At^4 At time t=0 the particle is at (R,0) . A. Find the distance that the particle has traveled as a function of time S(t) . B. Display the particle's acceleration...

Homework Statement I have this question to solve for homework : " An object of mass 10 kg is whirled around a horizontal circle of radius 4m" If the uniform speed of the object is 5m/s Calculate a) tension in string b) angle of inclination of string to the vertical.Homework EquationsThe Attempt...

Homework Statement Assuming the keys are moving in uniform circular motion![/B] Keys with a combined mass of 0.100 kg are attached to a 0.25 m long string and swung in a circle in the vertical plane. a)What is the slowest speed that the keys can swing and still maintain a circular path...

Homework Statement Given that the circular arc wire with radius 'r' has a linear charge density ##\lambda##. What is the Electric field at the origin? Homework Equations ##\vec{E}=\frac{kq}{r^2}## where ##k=9\times10^9## is a constant. 3. The Attempt at a Solution I took a small segment dy...

Homework Statement Hello there, So I have a problem that I can't seem to figure out on my own. I have no background in physics (I haven't taken a physics course as of right now,) but my robotics team requires some math. I need to find the equation for moving something with a mass of 1.5kg...

Homework Statement Picture:[/B] The Attempt at a Solution [/B] Can someone please help..There's no answers and I think my answer is very wrong, as you can see I have pretty much no idea what I'm doing. Thanks Edit: Where it says net force I meant to say net force per unit width. Edit2...

Hello, As of this moment I am trying to get in the process of writing an Extended Essay on Chladni Plates, more specifically on a circular vibrating membrane with free ends. To begin with I thought the concept could be simplified to such an extent where I could take a cross-section of the plate...

Homework Statement On a banked race track, the smallest circular path on which cars can move has a radius of 116 m, while the largest has a radius of 153 m, as the drawing illustrates. The height of the outer wall is 11.6 m. Find (a) the smallest and (b) the largest speed at which cars can move...

Homework Statement A centrifuge is a device in which a small container of material is rotated at a high speed on a circular path. Such a device is used in medical laboratories, for instance, to cause the more dense red blood cells to settle through the less dense blood serum and collect at the...

Homework Statement A 200g ball on a 55-cm-long string is swung in a vertical circle about a point 200 cm above the floor. The string suddenly breaks when it is parallel to the ground and the ball is moving upward. The ball reaches a height 600 cm above the floor. What was the tension in the...

Homework Statement In this question, the Earth is modeled as a uniform sphere of radius 6400km. Objects are released from points just above the Earth's surface at the equator and at the North Pole. Which will fall to the Earth with the greater acceleration and by how much? Homework Equations...