Circular Definition and 999 Threads

Homework Statement don't know the line integral latex code but; \int\underline{r}\timesd\underline{r} from (a,0,0) to (a,0,2∏b) on the circular helix \underline{r} = (acos(λ), asin(λ), bλ) The Attempt at a Solution Its the multiple use of the position vector r in the question...

Circular Motion and Static Friction Problem.. "The Wall of Death" ride Homework Statement A fairground ride called "The Wall of Death" consists of a cylindrical container of internal diameter 6.50m, mounted on a cylindrical axis. The passengers feel as if they are being pushed against the...

What I have ? Have a 16’ x 72’ rotating drum There is a solid circular sector inside the drum What I need ? Want to Calculate the torque required to move that solid circular sector from the intial position to the position shown in attached picture (90 Degrees rotation) Data ...

I am in need for some help for a lab report. The issue has happened because there is a lab of 20 students that is being led by a recently retired NASA physicist trying to lead a team of graduate student (or camel jockeys as he puts it) and the lab instructions are being botched horribly...

https://www.physicsforums.com/attachment.php?attachmentid=56184&d=1362060936 https://www.physicsforums.com/attachment.php?attachmentid=56185&d=1362060998 https://www.physicsforums.com/attachment.php?attachmentid=56186&d=1362061038 Any help of how to prove this problem would be...

Hi, I am carrying out a series of experiments which consist of a square plate object placed over a circular hole. The experiment is done in such a way that I can apply a point force at the center of the plate and see how much force is required to pull the plate through the hole. I should add...

Homework Statement A turntable of radius "r" is spinning counterclockwise at an initial rate of ω. at t=0, its rotation rate begins to slow at a steady pace. the rotation finally stops at t=T. At what time during the time interval 0<t<T was the magnitude of the centripetal acceleration of a...

If I have a series of pipes and containers (containing liquid) soldered together to create a circular path, and then heated at a particular point or multiple points, is it possible to somehow have the gas move in a particular direction without the gas every leaving the system? I'd prefer not to...

Homework Statement It is common to see birds of prey rising upward on thermals. The paths they take may be spiral-like. You can model the spiral motion as uniform circular motion combined with a constant upward velocity. Assume a bird completes a circle of radius 6.00m every 5.00s and rises...

Homework Statement A car is moving with constant velocity v, and has wheels of radius R. The car drives over a clump of mud and the mud with mass m, and sticks to the wheel with an adhesive force of f perpendicular to the surface of wheel. At what angle (theta) does the piece of mud drop off...

How exactly does radius affect centripetal acceleration? In one formula we have (a=v^2/r) which implies inversely proportional, while in the other we have (a=(w^2)*r) which implies directly proportional. I understand that increasing r increases velocity (v=w*r) which means the right answer is...

Homework Statement The aeroplane is traveling at a speed of 75 m/s and the radius of the turning circle is 80 m. Homework Equations Calculate the angle which the airplane wings make the with horizontal during the turn. The Attempt at a Solution I tried but I couldn't get to the...

Homework Statement A particle moves with constant speed v around a circle of radius b. Find the velocity vector in polar coordinates using an origin lying on the circle. https://www.desmos.com/calculator/maj7t9ple1 Imagine the r starts at (0,0). Homework Equations \frac{d\vec{r}}{dt} =...

Homework Statement A van is moving on a horizontal circular bend in the road of radius 75m. The bend is banked at arctan(1/3) to the horizontal. The maximum speed at which the van can be driven around the bend without slipping is 25m/s. Calculate the coefficient of friction between the road...

Hi, I am having problems with the following two problems: Homework Statement A 1.84kg ball is swung vertically from a 0.80m cord in uniform circular motion at a speed of 2.8m/s. What is the tension in the cord at the bottom of the ball's motion? Homework Equations I have tried using the...

Homework Statement A boy ties a rock to a 0.95 m string and swings it in a horizontal circle directly over his head so that it completes one revolution every 0.75 s. What is the tension in the string? So we know r and we can calculate V, but that's all I can deduce Homework Equations...

Homework Statement I am trying to derive the formula a_r=\frac{v^2}{r} for uniform circular motion (for personal understanding, this is not an assignment). But am having some difficulty. I have seen other proofs, but I want to know why my approach is wrong. The Attempt at a Solution...

Can you tell me if my answers and sign are correct ? A car is traveling around a horizontal circular track with radius r = 250.0 m at a constant speed v = 18.0 m/s as shown. The angle θA = 19.0° above the x axis, and the angle θB = 60.0° below the x axis. What is the x component of the...

You are traveling on an airplane. The velocity of the plane with respect to the air is 120.0 m/s due east. The velocity of the air with respect to the ground is 43.0 m/s at an angle of 30° west of due north. 1.What is the speed of the plane with respect to the ground? I got 82.76 by doing...

Homework Statement In my physics book (Young and Freedman 12 edition), in the chapter about conservation of energy, it teaches me that I can use the theory of conservation of energy and discover the velocity at the bottom of a circular path, having the height of this circular path. I...

Attached is a scan of how Balanis define plane wave with circular polarization with Ey having a phase of +∏/2 respect to Ex component of the E field. I don't quite agree with the book. The second attachment is my derivation. The definition of CW or CCW is with respect to direction of...

Homework Statement Let's say there's a uniform circular wire with radius r. There is a uniform force pushing outward from the center in all directions of the wire. This total force is 10N. What is the tension in the wire? Homework Equations N/A The Attempt at a Solution Let's say the...

Homework Statement A particle of mass M is on the top of a vertical circle without initial velocity. It starts to fall clockwise. Find the angle with respect to the origin, where the particle leaves the circle. Homework Equations v=ωXr The Attempt at a Solution I used two unitary...

how can rcosθ in a banked road be equal to mg; since r is equal to normal reaction which is equal to mgcosθ. rcos is even smaller than r. so mg>mgcosθ mgcosθ=r r>rcosθ so mg>rcosθ then how can mg=rcos when banking in curved road?

Should the driver apply brakes or turn the car in a circle of radius 'r' to avoid hitting the wall? This question is in the excercise of circular motion chapter. In this question I don't uderstand from where to start. Some help would be greatly appreciated.

Hi to everybody Homework Statement (The attachment has an image with this problem) A small probe P is gently forced against the circular surface with a vertical force F as shown. Determine the n- and t-components of this force as functions of the horizontal position s. Homework Equations...

Homework Statement A hollow circular cylinder of radius a and length b, with open ends, has a total charge Q uniformly distributed over its surface. What is the difference in potential between a point on the axis at one end and the midpoint of the axis?Homework Equations U = kq/r The Attempt...

Homework Statement A pilot of mass 50 kg comes out of a vertical dive in a circular arc such that her upward acceleration is 6g. (a) What is the magnitude of the force exerted by the airplane seat on the pilot at the bottom of the arc? (b) If the speed of the plane is 390 km/h, what...

Homework Statement What is the speed of the object (a bird) relative to the ground? We are given that a bird is flying in a spiraling path and rising on a thermal, making circles with a radius of 6m every 5s and rising strait up at a velocity of 3m/s.Homework Equations V=d/t C=2πr=d The...

Homework Statement Two small planets are moving in circular orbits around the same star. If the radius of the orbit of planet A is 4 times the radius of the orbit of planet B, find the ratio of their speeds vA/vB. Homework Equations Not really sure but v=omega*r a(centripetal)=v^2/r...

I'm writing a program that simulates circular "particles" in 2d space. I'm at the collision handling part. I've already corrected their positions when an overlap occurs. So, my question is, how do I determine the angle of each particle's velocity after the collision? I have the position and...

Homework Statement Here is the problem with my 3 attempts: 1. Alright, so the first attempt, I did not take into account the rotation of the cylinder ωc so I think it is wrong. But it seems to make sense because the whole cylinder rotates about O, so if I find that energy using parallel...

$u_{tt} = c^2\nabla^2u$ where $\nabla^2 = \frac{1}{r}\frac{\partial }{\partial r}\left(r\frac{\partial}{\partial r}\right) + \frac{1}{r^2}\frac{\partial^2}{\partial\theta^2}$. Suppose $u(r,\theta,t) = G(r,\theta)e^{i\omega t}$. Then $$ -\omega^2Ge^{i\omega t} = c^2\nabla^2Ge^{i\omega t} $$ which...

Homework Statement If you are spinning an object of mass 3.25 kg on a 0.8 m long chain at 20 rpm (vertical cirular motion), a) what is the tension at the top b) 43° from the top and c) at the bottom?Homework Equations String tension: T = Fc - mg cosθ Tension at top: T = (mv^2/r) - mg Tension at...

There's basically a beam of protons moving in the x-y plane, 30 degree from the +x-axis. The magnetic field is oriented in the +z-axis. So would the particle's motion be circular or helical? I say helical, because the velocity isn't completely perpendicular. Is this correct?

Homework Statement A small car with mass .800 kg travels at a constant speed of 12m/s on the inside of a track that is a vertical circle with radius 5.0m. If the normal force exerted by the track on the car when it is at the top of the track is 6.00N, what is the normal force at the bottom of...

Hi, Suppose we have a fellow on a ferris wheel. Would the normal force be greater on the top or at the bottom of the ferris wheel? I'm thinking that it would be greater at the top, or am I wrong? Thanks,

Homework Statement So my professor gave me this formula GMplanet = (v^2 x d)/a to solve for the question and told me that m/v = density. I was told then to multiply the end result of m by 1000 and v by 1,000,000 to get the answer. I am given all the knowns except the acceleration. How do i...

Homework Statement A manufacturer of CD-ROM drives claims that the player can spin the disc as frequently as 1200 revolutions per minute. a. If spinning at this rate, what is the speed of the outer row of data on the disc; this row is located 5.6 cm from the center of the disc? b. What is the...

Homework Statement Consider a small box of mass m sitting on a wedge with an angle θ and fixed to a spring with a spring constant k and a length in a non-stretched state L. The wedge rotates with an angular velocity ω around the vertical axis. Find the equilibrium position of the box...

Homework Statement I must find the oscillations of a circular membrane (drum-like). 1)With the boundary condition that the membrane is fixed at r=a. 2)That the membrane is free. Homework Equations The wave equation \frac{\partial ^2 u }{\partial t^2 } - c^2 \triangle u =0...

Homework Statement Find the exact values of the six trigonometric function of the given number. If a function is undefined for the number, say so. 11\pi/6Homework Equations The Attempt at a Solution The way I did it was to turn it into radians by simply doing the math... 5.76 radians Then...

Question 1 A box of mass 5.8 kg is pulled to the right with a horizontal force of 8.2 N. If the box moves to the right with constant velocity of 2.66 m/s, what is the frictional force acting on the box? Question 3 A person pulls on a 41 kg table with a 215 N force acting at an angle of...

When a substance has coefficient of refraction that depends on direction, a single ray of unpolarized light incident on its surface normally splits in 2 rays - no fewer except in case of specific directions where the 2 coincide, but also no more - which have different, linear, polarization...

Hai, I am doing my masters degree in physics. can somebody help me in which formula to use for calculating resistivity of a sample of circular shape using two probe measurements, which should include thickness and correction factor also. Thank You!

Homework Statement a 6 kg, originally held at rest in position 1 as shown in the diagram below, slides down a frictionless quadrant of a verticle circle of radius 15 m. It then collides elastically with another 16 kg mass at rest at position 2. They bounce off each other and move on the...

Hi guys , Suppose there is a circular accelerator has the same inner structure of a linear accelerator in terms of the rings of acceleration ... The angular frequency of accelerated particles is : ω = qB/m = 2πf , and this is also the supplied current frequency ... The question is ...

Homework Statement A circular profile with radius r is subjected to opposing compressive forces Fc in the x and y directions as show. If the material has compressive strength sigma_c = 2000MPA, at what compressive force Fc will the profile experience failure? Homework Equations...

Homework Statement What is the radius of a circular orbit about the Earth where the acceleration is 0.1g? Homework Equations g=9.8m/s^2 F=(Gmm)/r^2 Radius of Earth= 6.38x103 km Mass of Earth= 5.98x10^24 m/s The Attempt at a Solution I said 1/(2^x)=1/10 then did log2(10)=x and solved...

Hello how can I find the moment of inertia of a circular sector about the X axis , which the sector is symmetrical about , with -θ down and θ above ?! I_{x} = ∫y^{2} dA = ∫y^{2} *y *dx Or =∫∫ y^{2} dy dx I don't know how to put the limits of integration , I turned it to polar...