Angular Definition and 999 Threads

1.Homework Statement The wave function for a wave on a taunt string is: y(x,t)=(0.350)(sin(10(π)(t)-3(pi)(x) +(π)/4) where x and y are in meters and t is in seconds. If the linear mass density(μ) of the string is 75.0g/m, (a) what is tha average rate at which energy is transmitted along...

Homework Statement Hello all, Im asked to construct the state | \frac{5}{2} , \frac{3}{2} \rangle from the eigenfunctions | L, L_z\rangle and the electron states | \uparrow \rangle and | \downarrow \rangle . Homework Equations Clebsch Gordon Coefficient's table The Attempt at a...

Homework Statement Two objects with mass of m are connected with a rod with length 2l and with no mass. The center of the rod is pinned so that it can spin. Object with mass M comes with speed v and sticks to m. There is no friction. 1) What is the angular speed w after collision? 2) FInd the...

What would the angular velocity for a phasor be for a triangle wave? I think it would vary sinusoidally but I can't find an expression

Homework Statement Question - Models of global warming predict that large sections of the polar ice caps will melt. Explain what effect this will have on the rotation of the Earth, however slight. Homework Equations L = Iw The Attempt at a Solution Assuming polar ice caps protrude the earth...

Homework Statement Homework Equations Vθ = r x θdot Vr = rdot Accelθ = r ⋅ θdot^2 + 2(r dot)(theta dot) Accelr = r double dot - (r ⋅(θdot)^2) The Attempt at a Solution I know that the answer is supposed to be But I'm not quite sure on how I'm supposed to get to an answer like that. I'm...

Homework Statement Go to the following web site: http://www.astro.utoronto.ca/~cclement/cat/listngc.html This is the portal to a large on-line catalog of variable stars in globular clusters. Each link is a cluster name and will take you to a simple text page that lists near the top the...

Homework Statement Consider an electron with spin ##\vec{S}## and magnetic moment ##\vec{\mu}=-\frac{e}{m}\vec{S}##. It is moving with the velocity ##\vec{v}(t)## relative to the inertial frame of reference ##I## through the electric field ##\vec{E}##. Calculate the angular momentum the...

If there is no net torque acting on a system total angular momentum of the system will be conserved as well as angular momentum of each body present in the system will be conserved. And if there are two bodies /two charges present as a system and one of them (let's say body 1 )produces torque...

I like a to ask a very simple question. I have read about time-dilation when it comes to SR. So, like: (1.) A and B are are rest and close to each other. (2.) B starts traveling at .5C relative to A, away from A, in a straight line. (3.) B comes back at .5C towards A. Now, according to SR, A...

Homework Statement . What is the angular acceleration if a force of 3 N is applied perpendicular to the radius of a 5 kg solid sphere that has a radius of 0.6 meters? Homework Equations = r x F I = mr^2 The Attempt at a Solution I used tried solving for angular acce. 3N/(5kg)(0.6)...

Homework Statement I am trying to show that as the alpha particle is being scattered, the angular momentum magnitude at point M is m r^2 \frac{d \phi}{dt}. Diagram: Homework Equations Linear Momentum: ##\vec L = \vec r \times \vec p ## Repulsive Coulomb Force: ##\vec F = \frac{k 2Ze^2}{r^2}...

Homework Statement A sprinter runs the curve of this 200 m in 11.61 s. Assume he ran in a lane which makes a semicircle (r = 32.4 m) for the first part of the race. At 3.59 s into the race his speed is 5.9 m/s. At 7.9 s into the race his speed is 8.4 m/s. His speed after the curve was 12.4 m/s...

Putting spin on the ball improves it’s stability (the spin imparts angular momentum and it takes an outside torque to change angular momentum), but at a cost. As you know, for a given input of energy, spin consumes some of that energy and leaves less for translation. Part A: So, How much more...

Homework Statement An airplane makes a circular turn of radius 9 km at a constant speed of 650 km/h. Calculate the magnitude of the plane's a. angular velocity, b. centripetal acceleration, c. angular acceleration, d. tangential acceleration Homework Equations w = v/r aR = w^2r The Attempt at...

orbital movement occupy more space than spin movement. If an object are running in both orbit and spin, how to stop orbit and transfer orbit energy to spin energy? Of course the total angular momentum conserves. I know new optical technology can convert spin energy into orbital energy, but it...

Homework Statement : [/B] A vector is perpendicular to B vector, and they stay still, relative to the body. No torque is applied on the asteroid, although he dissipates very little rotational kinetic energy, due to drag on dust clouds. It was also determined that the asteroid is a long body...

Homework Statement Attached Homework Equations ##J_+|j,m⟩ = ћ\sqrt{j(j+1)-m(m+1)} |j,m+1⟩## ##J_-|j,m⟩ = ћ\sqrt{j(j+1)-m(m-1)} |j,m-1⟩## ##J_z|j,m⟩ = mћ |j,m⟩## ##J^2|j,m⟩ = ћ^2j(j+1) |j,m⟩## The Attempt at a Solution Hi there, For part a, the expression we're looking for is given, but...

Homework Statement Is angular momentum of a projectile in projectile motion conserved ?[/B]Homework EquationsThe Attempt at a Solution Gravitional force vector is acting along direction of displacement vector. Thus external torque is 0. Thus angular momentum is conserved throughout projectile...

Hi! I am struggling with this problem the last two days and I cannot decide which solution is correct. Homework Statement A cylinder of radius R is fixed horizontally on the floor. A uniform chain of mass M and length L (L<πR/2) is placed on the cylinder in such a way that one end of the...

If we were living in a two dimensional world. would we know about angular momentum of an object?

Homework Statement After happily working my way through the earlier parts of this question, I'm pretty much at the end of my tether with the last two parts. Please find the diagram attached: A) Determine the value of the angle θ (measured from vertical) when the angular velocity of link AB a...

Homework Statement This is a general query not a specific problem. In several questions in rotational dynamics they ask the trend in angular acceleration and angular velocity.In one of them they released a rod from horizontal position and asked if the angular velocity and angular acceleration...

Homework Statement A rotating beacon is located 1 kilometer off a straight shoreline (see figure). If the beacon rotates at a rate of 3 revolutions per minute, how fast (in kilometers per hour) does the beam of light appear to be moving to a viewer who is 1/2 kilometer down the shoreline...

Homework Statement Is it possible for the respective angular momenta of each individual particle in a system to be zero, but the system's collective angular momentum be nonzero? For example, a puck on a frictionless air table moves (without spinning) toward a point on a rod that is not the...

When a nucleus gamma decays, the gamma has its intrinsic spin of ##1\hbar##, but it can also carry away a significant amount of angular momentum in addition to that. Quadrupole radiation is very common, and in exceptional cases you can even get gammas with 5 or ##10\hbar##. Now suppose I do the...

I've been working on my SR book http://www.lightandmatter.com/sr/ and its presentation of a suite of related mathematical tools such as the Levi-Civita tensor. This is aimed at the upper-division undergraduate level, although there are optional sections at the end of some of the chapters that go...

Homework Statement https://scontent-sea1-1.xx.fbcdn.net/hphotos-xft1/v/t35.0-12/12414351_10206719685063143_386848762_o.jpg?oh=16c004481b7417fad921c37acc4942be&oe=56793416 Homework Equations Angular momentum: H= Iw Parallel axis theorem: Io = I + Md^2 Moment of Inertia of thin plate about it's...

Hi, Two questions. 1) I'm having trouble understanding the stability of the stable Lagrangian points (L_4 and L_5); Wikipedia explains that if an object in the L_4 or L_5 of a planet is pushed closer towards the common center of gravity of the Sun and the planet, the increased speed that comes...

I'm having a hard time undertanding a concept of moment of inertia and Angular acceleration. Homework Statement We have a closed system above. M1 is a cylinder of 2 Kilograms, moment of inertia of a cylinder ( MR2 /2 ) with a string tightly rolled around it. This string connects to a free...

Homework Statement A rod that is fixed to a vertical wall is attached through the middle of a solid disk. A piece of the disk crumbles off when the disk is spinning and rises vertically. The system is the chip and the spinning disk. Assume no friction. A. How does the direction of the angular...

Homework Statement A discus thrower ( with arm length of 1.2 m) starts from rest and begins to rotate counterclockwise with a constant angular acceleration of 2.5 [rad/s^2]. What is the magnitude of the total acceleration of the discus when its angular velocity is 9.0[rad/s]? Homework...

Dear guys, Recently, i am confused with a problem in my textbook of mechanics. The question is, suppose there is a disk, placed horizontally, rotate about its center with angular velocity ω. A ball move with respect to the center of the disk in a trace of Archimedean spiral r=αθ. The angular...

Homework Statement 2. The attempt at a solution I set the initial angular momentum of the disk = to the sum of : rod's angular momentum, angular momentum of disk, rod's center of gravity and disk's center of gravity. With the reference point being at B. Why is the velocity of the rod's...

Homework Statement A device consists of eight balls each of mass 0.6kg attached to the ends of low-mass spokes of length 2.1m, so that the radius of rotation of the balls is 1.05m. The device is mounted in the vertical plane. The axle is held up by supports that are not shown, and the wheel is...

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...

I would like to prove that the angular momentum operators ##\vec{J} = \vec{x} \times \vec{p} = \vec{x} \times (-i\vec{\nabla})## can be used to obtain the commutation relations ##[J_{i},J_{j}]=i\epsilon_{ijk}J_{k}##. Something's gone wrong with my proof below. Can you point out the mistake...

Homework Statement A block of mass 2kg (mb) can slide down a frictionless 53 degree inclune, but it is connected to a pulley of mass 4kg (mp with a radius of 0.5m. The pulley may be treated as a disk. What is the angular acceleration of the pulley? Homework Equations a = rα The Attempt at a...

Homework Statement [/B]Homework Equations L = I ω L= r x p The Attempt at a Solution For b) My proffesor found the moment of inertia at the point at which the wheel touches the ground, and used the formula L = I ω What I don't understand is why can't one use L= r x p to solve the...

Homework Statement Indiana Jones standoff. Person A fires a 20g bullet at 500 m/s at Person B, who is holding a sword. The bullet sticks to the sword. The angular momentum of the sword is 2.225 kgm^2 / s. The moment of inertia about the center of mass of the sword is .7082 kgm^2. The...

Homework Statement Homework Equations αt = r α The Attempt at a Solution ωi = 0 rad/s αt = 2.00 rad/s2 r = 112 m θ = ? at a = 6.80 m/s2 I'm not exactly sure where to begin. Help is appreciated.

Homework Statement A solid sphere is rolling without slipping on rough ground with an angular velocity w and linear velocity v. It collides elastically with an another identical sphere at rest. Radius of each sphere is R and mass m. What is the linear velocity of the first sphere after it...

Homework Statement A metal bar of length r is attached to a pivot point at (0,0) in the XY plane. A steel ball is projected toward the free end of the rod and strikes it at the tip. Show how to calculate the angular acceleration of the bar after the collision and draw a vector diagram to scale...

I know that the angular momentum is conserved in the below example, but intuitively I am struggling. Anyway, here goes! Homework Statement A bullet that is traveling without spinning hits and sticks into a filled disk tilted on its side an arbitrary distance "d" away from the center of mass...

Homework Statement A 2.0-m measuring stick of mass 0.175 kg is resting on a table. A mass of 0.500 kg is attached to the stick at a distance of 74.0 cm from the center. Both the stick and the table surface are frictionless. The stick rotates with an angular speed of 5.30 rad/s. (a) If the...

Good morning, I have an iron bar (35 cm long) hinged on an axis. The path of this bar is limited to 45 degrees. I have to measure the angular velocity of the bar when it rotates 45 degrees. I need to get a graph of variation of the angular velocity along the 45 degree paths. The time taken to...

Homework Statement A particle of mass m moves under the influence of a central force F(r)=-mk[(3/r^2)-2a/r^3]rhat Show that if the particle is moving in a circular orbit of radius a, then its angular momentum is L=mh=m√(ka) Homework Equations L=mvr for circular orbit The Attempt at a...

Homework Statement A 1.15-kg grinding wheel 22.0 cm in diameter is spinning counterclockwise at a rate of 20.0 revolutions per second. When the power to the grinder is turned off, the grinding wheel slows with constant angular acceleration and takes 80.0 s to come to a rest. (a) What was the...

Starting with the orbital angular momentum of the ith element of mass, $ \vec{L}_I = \vec{r}_I \times \vec{p}_I = m_i \vec{r}_i \times \left( \omega \times \vec{r}_i\right) $, derive the inertia matrix such that $\vec{L} =I\omega, |\vec{L} \rangle = I |\vec{\omega} \rangle $ I used a X b X c...

Hi all, please help me here! Im confused, is direction of angular velocity perpendicular to the plane of motion, or along the plane of motion?? From hyperphysics - http://hyperphysics.phy-astr.gsu.edu/hbase/rotq.html -...