Circular Definition and 999 Threads

Homework Statement A) An object moving along the x-axis is acted upon by a force Fx that varies with position as shown. How much work is done by this force as the object moves from x = 2 m to x = 8 m? B) A 50-kg child riding a Ferris wheel (radius of wheel R = 10 m) travels in a vertical...

If you are twirling a rock around your head with a rope (assuming it is uniform circular motion), then the only acceleration that is acting is radial. So if you take a look at the rock at any given instant, its velocity is perpendicular to its acceleration. My question is, why does the rock not...

Homework Statement An object is launched horizontally from the highest peak on the Moon's surface. Calculate (a) the launch speed required so that the object travels completely around the Moon and returns to its original position, and (b) the time required to return to the launch point. Assume...

Homework Statement A sphere of radius R = 1.40 m surrounds a particle with charge Q = 42.0 μC located at its center as shown in the figure below. Find the electric flux through a circular cap of half-angle θ = 28.0°. Homework Equations Φ = ∫E⋅dA E = (kq)/r2 A = πa2 where a = rsin(θ) --> from...

Homework Statement Homework Equations F= mv^2/r v = angular vel* r The Attempt at a Solution resultant force= ma-frictional force = mv^2/r - mg*meu = (angular vel)^2mx - mg*meu But then how do I get the angular speed when I don;2 know the resultant...

1. Homework Statement We are studying circular states of the hydrogen atom (states where the l quantum number is = n-1). We are asked to evaluate \langle \Psi_{n,n-1,n-1}| r_{n,l=n-1}|\Psi_{n,n-1,n-1}\rangle . The wave function is that of the hydrogen atom, and the thing we are taking the...

Homework Statement The loop-the-loop machine has radius R of 18m (a) What is the minimum speed at which a cart must travel so that it will safety loop the loop (b) what will the speed at the top be in this case Homework Equations Centipetal force = m*v^2/r Kinetic and potential energies =...

Use an appropriate volume integral to find an expression for the volume enclosed between a sphere of radius 1 centered on the origin and a circular cone of half-angle alpha with its vertex at the origin. Show that in the limits where alpha = 0 and alpha = pi that your expression gives the...

If current I passes through a circular loop of radius R,then what will be the self inductance of that loop? (calculating flux through the loop leads to calculating magnetic field at every point inside the loop which is an elliptic integral.)

Homework Statement If a roller coaster car enters the circular-loop portion of the ride and navigates it successfully, then the net force on the car at its topmost point is straight down. Then why does not the car fall down? So I am having issues understanding my textbook's solution to the...

Hi, I have been studying up on circular motion in the vertical plane and I am happy with all the math/theory that I have read explaining the normal force and weight force and the feeling of being "heavier" and "lighter". My question is about the top of the hill/ride, The forces acting on you at...

Homework Statement We are given that system of 1st grade 1/2 * dy(t)/dt + y(t) = x(t) 1) We need to find frequency response { H(w) } 2) We need to find circular frequency -3dB 3) We need to find the absolute value of H(w) in dB for frequency f = 3/π Hz 2. Homework Equations (log is always...

Homework Statement Ball of mass=m on the frictionless table is connected to a string that passes in hole that is in table. The ball is set into a circular motion on a circle of radius = R. If the string pulled from the bottom, withe the force F, so that the radius of motion of ball would...

Homework Statement A wheel spins at an angular speed of 2.50 rad/s for a total of 30.0s. How many complete revolutions will the wheel make during this time? A) 31.4 rev B) 19.3 rev C) 11.9 rev D) 75.0 rev Homework Equations W=Wo+(alpha)(t) θ=θo+Wot+1/2(alpha)t^2 W^2=Wo^2+2(alpha)(θ-θo) The...

What's the solution to the wave equation for circular waves on a two-dimensional membrane? The waves have a constant wavelength throughout. For spherical waves, you have to multiply the amplitude by 1/r. I tried 1/√r for circular waves but it didn't work. :blushing:

Homework Statement A car travels on a circular track at 20m/s. The track has a circumference of 2.0km. What is the average velocity of the car over one lap? Homework EquationsThe Attempt at a Solution Since the car is traveling at a constant speed of 20m/s, wouldn't the average velocity be...

please explain why? Take 2 cases,and explain how is the direction of friction different in these 2 cases. CASE 1:uniform circular motion CASE 2:non uniform circular motion my thought was,friction opposes relative motion,so it must be tangential to the particle at each and every point. i very...

Time-varying magnetic field makes electric field circular(or close loop). I am asking the reason why it is circular or close loop shape?

This is a follow on to a prior thread, Another circular twin paradox Consider a train of proper length 100 at rest in an inertial ground frame. It is accelerated Born rigidly to the right on a straight track to 0.6c in the ground frame, after which is still has proper length 100 but has now...

I don't really understand the difference between uniform circular motion and rotational motion. I know that uniform circular motion deals with a body that is orbiting around a central point, with a centripetal force that is causing it to move in a circle. I know that rotational motion uses...

Homework Statement A mass m1= 0.200 kg is tied to a string with enough slack to swing around someone's head with a radius of 0.500 meters. What angular velocity must m1 have in order to hold up a mass m2 hanging from the other end of the string if m2 is 0.300 kg?Homework Equations ac= v^2/r...

Homework Statement A car travels along the perimeter of a vertical circle (radius = 0.25 km) at a constant speed of 30 m/s. What is the magnitude of the resultant force on the 60-kg driver of the car at the lowest point on this circular path? Question options: 1) 0.37 kN 2) 0.80 kN 3) 0.22 kN...

The Euler-Lagrange equations give a necessary condition for the action be extremal given some lagrangian which depends on some function to be varied over. The basic form assumes fixed endpoints for the function to be varied over, but we can extend to cases in which one or both endpoints are free...

Here is a scenario in which two twins age at different rates even though both always have the same speed.Consider a train track that includes a circular segment with ground circumference minutely greater than 80. Two twins are on a train with synchronized watches (Frank at the front and Reba at...

Two satellites A and B move around Earth in a circular orbit. The mass of B is twice the mass of A then I agree that kinetic energy of B is greater than that of A. But what I couldn't understand was that why are speeds of A and B equal as given in the book. Shouldn't they differ according to the...

Homework Statement A 50 g weight is swung in a circle on the end of a 90 cm long string at the speed of 5.9 m/s, what is centripetal force? [1.9 N] Homework Equations Vc = (2πr)\T |a| = v^2/r Fc = T-Fg (not sure if T is force of tension or period, my teacher,incorrectly,uses it...

Homework Statement A circular loop of radius R is on the xy plane and the center is at the origin, the current is flowing in a counter-clockwise manner. a) Let Q=(a,0,a) be a point such that a>>R. Find Br and Bθ at Q. b) Let Q=(ha,0,0) be a point on the x-axis such that h<1. Find the vector...

Mentor's note: Post moved to new thread since it's a new problem. One more problem Homework Statement Find the equivalent capacitance between A and B. Homework Equations The Attempt at a Solution I think all the Capacitors are in series but according to my book only three capacitors are in...

Homework Statement Describe the relationship between the resulting torque from each scenario using the torque equation. Question this question is addressing- Using the bricks from the materials on the right, create and record 10 different combinations of two unequal masses that result in a...

For a vertical circular motion, its standard to solve for tension at the 4 common points on the circle (North, South, East, West) My question is, is it possible to solve for tension at other locations? Example :https://www.dropbox.com/s/c4q1sprphol2tzb/20151127_020345.jpg?dl=0 Can i resolve...

Hi. I am having some difficulty with circular motion.An object is spun vertically on a rope a) when would the string be most likely to break? The object would most likely to break when it has the most tension, so at the bottom of the circle it is Ft-Fg=Mv^2/r which is (Ft=Mv^2/r + Fg) while the...

Homework Statement A car of mass (m) is attached to a cable of length (L) to a rotating pole. The car will speed up and travel in a circle. If the maximum speed of the car is vmax, what should the minimum strength of the cable connecting the car to the pole be? Note the surface is not...

Homework Statement For a scene in a movie, a stunt driver drives a 1.20✕ 103 kg pickup truck with a length of 4.65 m around a circular curve with a radius of curvature of 0.333 km (Fig. 7.29). The truck is to curve off the road, jump across a gully 10.0 m wide, and land on the other side 2.96 m...

Hi everyone, 1. Homework Statement Homework Equations 1) centripetal acceleration = v^2 / R 2) centripetal acceleration = 4 pi^2 R / T^2 3) average velocity = displacement / time[/B]The Attempt at a Solution For #1a I first found the displacement of A to B. And then divided that by...

Homework Statement http://i.imgur.com/Nbg3Nrc.jpg pic of question Homework Equations v = wr, s=rtheta t=1/f etc The Attempt at a Solution i did a, got 504 radpersec and then did b, r = 1.3sin40 i - 1.3cos40 j + 0 k but I'm not sure if I'm doing it right. can anyone help me and point me in...

Hello, i want to determine the velocity with which an object moves after it has departed a rotating disk. In my problem there is a disk rotating with the angular speed w. On this disk there is a drilling in which a mass m is positioned. In case the thread in the drilling fails i need to...

hi, I'm currently talking about light, and I'm trying to find out if there is a material or a method that can flip a polariser's polarisation... ie, if i apply a current, then this crystal changed from a clockwize polariser to an anti-clockwize polariser, and it is either a plastic or elastic...

Homework Statement The electron enters a straight pipe of circular cross section (radius r). The tube is bent at a radius R≫r by the angle α and then is aligned back again. Find the probability that the electron will jump out Homework Equations Tunneling probability in WKB approximation. The...

Homework Statement A long straight wire carrying a constant current I1 and a circular wire loop carrying a constant current I2 lie in a plane. The radius of the loop is R, and its center is located at distance D from the straight wire. What is the magnetic force exerted on the loop by the...

http://edugen.wileyplus.com/edugen/courses/crs7165/art/qb/qu/c29/pict_29_93.gif if I wanted to find the area of the outer circular strip, I know I would just take the area of the composite and subtract out the inner radius. (i.e. pi(a^2)-pi(b^2)). However why can't I use...

Homework Statement Picture- https://flic.kr/p/zi1ays The rubber stopper will be spun at a constant speed in a horizontal circle. The hanging mass is only in contact with the string.[/B] A) For the rubber stopper, state the forces and what they are exerted by and on B) Does the net force have...

I have been wanting to write an equation which predicts the tension on a circular membrane (AKA drumhead). However, I'm not sure that my answer is on the right kind of track, if it's even correct. As for the procedures I took, first I started with the equation for tension on a string, which I...

Homework Statement This isn't a problem from a textbook or homework but just a general question. Say there's a car traveling in a circle and that the track has some coefficient of kinetic friction µ. What would make the car skid? Homework EquationsThe Attempt at a Solution I'm thinking that...

Homework Statement Hello, i got three different assignments i need help with right now, my teacher overestimated me and my physics skills, so I'm kind of lost on these three: (i'm european so i work with meters) 1: A planets radius is 10 000 km. the gravitationalacceleration is g0 = 15 m/s^2...

Homework Statement A rollercoaster consists of a 45 degree slope that is 100 m long followed by two loops which have radii of 40 m and 20 m respectively. If the rollercoaster accelerates down the initial slope due to gravity, determine: a. The acceleration of the rollercoaster down the 45...

In a non-uniform circular motion (for example a pendulum), can the centripetal/radial acceleration ever be 0? Likewise, can the tangential acceleration ever be 0? The centripetal acceleration occurs because of the centripetal force, which causes the body (in the example of the pendulum, the...

In a non-uniform circular motion (for example a pendulum), can the centripetal/radial acceleration ever be 0? Likewise, can the tangential acceleration ever be 0? The centripetal acceleration occurs because of the centripetal force, which causes the body (in the example of the pendulum, the...

Homework Statement A block of mass M=2kg with a semicircular track of radius R=1.1m rests on a horizontal frictionless surface.A uniform cylinder of radius r=10cm and mass m=1kg is released from rest from the top most point .The cylinder slips on the semicircular frictionless track.The...

Homework Statement Homework Equations Fnet=m(v^2/R)[/B]The Attempt at a Solution I understood the FBD and how to find the bank angle. I just don't fully understand what part a and b are giving me in terms of friction. So for a, since it is skidding would only kinetic friction be used? Then...

Hello, Here is a thing I'm confused about. when I first knew about centripetal force and satellites. I thought of it the exact way like projectiles. I thought like :satellites do fall. If we specify a single direction, the magnitude of the velocity is really changing. I thought of its path that...