Angular Definition and 999 Threads

  1. jisbon

    Conservation of angular momentum?

    Not sure what to do here, except using the conversation of angular momentum. Even then, is angular momentum conserved in this case even after attaching an external object here? Else, what laws can I use to solve this problem? Using conversation of angular momentum: $$\dfrac...
  2. Comeback City

    I Angular Momentum in a Solar Nebula

    Hello all! Hope everyone's been doing well! My question relates to the nebular theory of solar system formation. It is generally accepted that via the nebular hypothesis, matter in a nebula contracts on its own gravity and begins to spin, but I'm having trouble understanding why it must begin...
  3. A

    What is the Angular Momentum of a Baseball?

    k̂ direction = 0 kg*m^2/s ĵ direction = 0 kg*m^2/s î direction = (0.145kg) (20m/s) (6m) = 17.4 kg*m^2/s
  4. A

    Kinematics and angular speed of a collision between a rod and puck

    initial total KE= (1/2)(0.6kg)(8m/s)^2 = 19.2J (0.6kg)(8m/s) = (0.6kg+1.8kg)(vf) vf= 2m/s final KE= (1/2)(0.6kg+1.8kg)(2m/s)^2 = 4.8J I tried to use linear speed=angular speed * radius : thus 2m/s= angular speed * (3.3m/2) angular speed= 1.2 rad/s Apparently that is wrong.
  5. Negatratoron

    I Uncertainty between position and angular frequency - is this correct?

    Motivation: In my thermodynamics + statistical physics class, we derived the equipartition theorem for ideal gasses using Boltzmann factors, dividing the phase space of a gas particle in position+momentum space into units of size x*p=h based on the quantum nature of the space of states that are...
  6. A

    Angular momentum of a falling ball

    (L) = (radius) * (mass*velocity) velocity= 0+ (9.8m/s^2) (0.7s) = 6.86m/s (L) = (0.77m) * (2kg*6.86m/s)= 1.05 kg*m^2/s angular momentum points towards Polly
  7. H

    I Matrix Representation of the Angular Momentum Raising Operator

    In calculating the matrix elements for the raising operator L(+) with l = 1 and m = -1, 0, 1 each of my elements conforms to a diagonal shifted over one column with values [(2)^1/2]hbar on that diagonal, except for the element, L(+)|0,-1>, where I have a problem. This should be value...
  8. E

    Does an impulse contribute to both linear and angular momentum?

    As an analogue, if 5J of work is done on an object then the linear KE might increase by 2J and the angular by 3J, so the work is divided between the linear and rotational forms. Now suppose there is a sphere sliding on a frictionless surface. If an impulse of magnitude 1Ns is applied to the...
  9. A

    Angular speed, acceleration, and angle of a Ferris wheel

    ω(10)=(1.3)∗(1.0−e^(−10/22) )= 0.475 rad/s 0.475 rad/s=0 +α(10second) α=0.0475 rad/s^2 ∫ω(t)=Θ =1.3t + 28.6e^(-t/22) | (t=10s, t=0) total angle by which the wheel rotates over this period of t=10 seconds = 2.55 rad Θ= 2(pi)(8m)= 1.3t + 28.6e^(-t/22) 0=1.3t + 28.6e^(-t/22) - 2(pi)(8m) t=34...
  10. A

    Angular acceleration and velocity in a circle

    33.33 RPM (1min/60second)(6.28 radian/1 revolution) = 3.45 rad/s linear velocity=3.45 rad/s * 0.1524m=0.526 m/s linear acceleration= (0.526 m/s)^2 /(0.1524m)=1.814 m/s^2 1.814 m/s^2=(0.1524m)(rotational acceleration) rotational acceleration=11.9 rad/s^2 ω1= (3.45 rad/s)+(11.9rad/s^2)(10s)...
  11. Santilopez10

    Angular momentum of a mass-rope-mass system

    1) the motion equations for ##m_2## are: $$T-m_2 g=0 \rightarrow T=m_2 g$$ ##m_1##: $$T=m_1\frac{v^2}{r_0} \rightarrow \vec {v_0}=\sqrt{\frac{r_0 g m_2}{m_1}}\hat{\theta}$$ 2) This is where I am stuck, first I wrote ##m_2## motion equation just like before, but in polar coordinates...
  12. Clay Gillespie

    B Angular Meteorite Strikes on the Moons Surface

    Summary: An explanation into the mechanisms that make irregular shaped meteorites, including some up one tenth the size of the moon, seemingly vanish, leaving symmetrical craters with surprisingly shallow floors. We’re going to look at the initial conditions of the moons formation from the...
  13. Like Tony Stark

    Finding angular velocity for a rope to be cut

    I wrote Newton's equations for each body (I took ##x## as the axis aligned with the tension) ##m_1##: ##x)f*_1 -T_1+T_2=0## Where ##f*_1=\omega ^2 r_1## ##m_2## ##x)f*_2 -T_2=0## ##x)f*_2=T_2## Where ##f*_2=\omega ^2 r_2## I wrote that ##T_2=1100 N## and solved for ##\omega##, and I got...
  14. U

    The Angular Momentum of an Electric and Magnetic Charge

    Relevant Equations: Angular momentum density stored in an electromagnetic field: $$\vec{l}_{em} = \epsilon_0[\vec{r} \times (\vec{E} \times \vec{B})]$$ Electric field of an electric charge: $$\frac{q_e}{4\pi\epsilon_0}\frac{r - r'}{|r - r'|^3}$$ Magnetic field of a magnetic charge...
  15. Like Tony Stark

    Finding the angular velocity of a rotating arm

    A) The slider experiments three forces, all of them are on the ##x## axis (considering ##x## axis as the axis aligned with the arm): Normal force (exerted by the support), elastic force and centrifugal force, which is ##m.(\omega^2 r)## Elastic force is equal to ##Fe=-k \delta =-2 (R-2R)=2R##...
  16. jisbon

    Finding angular velocity when the CM is directly below the pivot

    So first of all, I will have to find the centre of mass. ##X_{cm} = \frac{1}{M}\int x dm## likewise for Y. ##M## =150kg From the above-given points, I can find the equation of a line to be ## y =-\frac{3}{4}x +3## . Area density = ##150kg/(0.5*4*3) = 25kg/m^2## ##X_{cm} = \frac{1}{M}\int x dm...
  17. jisbon

    Conservation of Angular Momentum

    Hi, Since this is a question about COAM (Conservation of Angular Momentum), I will assume I can leave out the part on translation and just use the formula below: ##Initial Angular Momentum= Final Angular Momentum## whereby ##I = \frac {1}{12}ML^2## (of rod) So, ##\frac {1}{12}ML^2(1.5)=\frac...
  18. Seth Greenberg

    What is the angular velocity in the center of a rotating 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?
  19. jisbon

    Circular motion -- Find the angular velocity at t=3

    Hi everyone. Do correct me if I am thinking wrongly. So to find angular velocity, won't I just have to integrate angular acc = 2t, which means angular velocity = t^2? Hence, won't the answer be 3^2=9? The answer seems to be 5.43 :/ Thanks
  20. Manasan3010

    Linear momentum or Angular Rotation

    I think the answer is ##\frac{mV}{M}## but I am not sure. Won't the cylinder tries to rotate due to the collision at one end? Is this anything related to Angular Momentum? The Answers given were,
  21. Z

    Difference between gyroscope angular displacement and Euler angles

    Hi guys, I'm trying to understand between gyroscope angular displacement and euler angles? for example { Δx = Δx + h * Rx * SCx);} this is gyroscope output about anguler displacement.This value can be used to determine angle that device created.Why we should euler angles to fly.(I know...
  22. S

    Relation between mass distribution and angular velocity

    Is E the correct answer because I think angular velocity is independent of mass distribution of the object? Thanks
  23. Alfredo Tifi

    I The Symmetry of Angular Momentum Conservation

    I suppose that the principle of conservation of angular momentum holds also for a cloud of particles weekly interacting at low pressure, density and temperature. And it should be still applicable when the particles or the atoms would start condensing and forming fusion products or simply solid...
  24. V

    Automotive The "pendulum turn": angular momentum or rotational energy?

    There is a cornering maneuver in rallying called the "Scandinavian flick" or the "pendulum turn". It involves steering away from the corner before actually steering into the corner. This creates a pendulum effect which makes the car turn more sharply into the corner. Sorry for the poor video...
  25. S

    Spinning objects and angular acceleration

    I believe I know that when an object, in terms of linear motion, accelerates, it is being resisted by inertia, thus creating so called fictitious forces. Now, that said, how does angular acceleration affect spinning objects like say, a gymnast, when they spin around the axis of rotation? Do they...
  26. R

    Torque, angular momentum and a fixed axis-of-symmetry requirement

    I'm reading through "University Physics 14th edition" by Young and Freeman. Section 10.5 on angular momentum for a rigid body around a fixed axis of rotation is derived as L = Iω. However, it shows that this is only the case for the fixed axis of rotation being an axis of symmetry. In section...
  27. G

    Calculation of minimum angular velocity of a mass on a spinning plate

    Problem Statement: How to calculate minumum angular velocity of a mass on a spinning plate Relevant Equations: f=mrw^2 Hi, here's the question: a) A rough horizontal plate rotates with a constant angular velocity of w about a fixed vertical axis. A particle of mass m lies on the plate at a...
  28. samm12345

    What is the final angular velocity of each cylinder

    Problem Statement: The uniform 4-kg cylinder A, of radius r = 150 mm, has an angular velocity w = 50 rad/s when it is brought into contact with an identical cylinder B which is at rest. The coefficient of kinetic friction at the contact point D is uk. After a period of slipping, the cylinders...
  29. Benjamin_harsh

    How Does Earth Maintain Its Angular Momentum After the Sun Disappears?

    In this video, around 2:28 He explains Earth maintain its same angular momentum even after sun disappears. I didn't get it. How Earth maintain its same angular momentum even after sun disappears?
  30. pobro44

    Angular and orbital speed at perihelion

    Hello to all good people of physics forums. I just wanted to ask, whether the angular and linear (orbital) speed in perihelion of eliptical orbit are related the same way as in circular orbit (v = rw). If we take a look at the angular momentum (in polar coordinates) of reduced body moving in...
  31. P

    Kepler's laws and proof using angular momentum

    a) Kepler's first law states that a planet like Earth displays an elliptical orbit with the sun in focus. Using M = dL/dt, prove that a planet cannot leave its plane of orbit. Note: M here is an externally applied torque that the sun exerts on the planet. diagram of the situation described b)...
  32. sandmanvgc

    Dynamics: Angular Acceleration Problem

    Both point A and B are moving in parallel in same direction, therefore rod is not rotating at this instance and angular acceleration is 0. Question states angular velocity is equal to zero. Plugging into Angular Acceleration"AB" = r*sqr(angular velocity"AB") = 0.26m* sqr(0) = 0 [Moderator's...
  33. Gbox

    Prove: angular momentum is preserved

    3. Find the hamilton equations 4. using 3. prove the the angular momentum in the z axis ##L_z=m(x\dot y-xy\dot)## is preserved. I got in ##3##: How can I prove 4?
  34. JD_PM

    I Angular momentum of an Odd-Odd nucleus (in its ground state)

    What I know is the following: The total angular momentum of the nucleus is just the total sum of the angular momentum of each nucleon. If the nucleons are even the total angular momentum in the ground state will simply be ##0+##. If the odd number of nucleons is close to one of the magic...
  35. EEristavi

    Energy Conservation in Angular motion / Moment of Inertia

    I write Conservation of Energy: Potential Energy loss(change): U = m g ##\Delta##h = m g (R+r) (1-cos##\alpha##) kinetic Energy gain(change): K = (##\frac {m v^2} 2## + ##\frac {I \omega^2} 2##) + (##\frac {M v_2^2} 2## + ##\frac {I_2 \omega_2^2} 2##) U = K m g (R+r) (1-cos##\alpha##) =...
  36. M

    Calculate the Angular Velocity of an Arm from a Data Set

    Hi, a newbie to the site and hoping someone can help. Its been a long time since I studied physics or math at school. I am having some difficulty calculating the angular velocity of the arm trhough a partial movement (phase). The data set I have separates the angular velocity into the three...
  37. D

    MHB Angular Velocity - 2100 Revs in 3 Mins - 73.3 Rad/s

    (i) A rotating machine shaft turns through 2100 revolutions in 3 minutes. Determine the average angular velocity, w, of the machine shaft in rad/s. the answer for this is 2100 x 2 pie = 4200 pie radian 3 mins = 180 seconds 4200 / 180 = 73.3 rad/s (ii) Determine the area and arc length of the...
  38. NP04

    Angular Momentum in an Inelastic Collision

    I was wondering why in the video the moment of inertia for the clay ball (upon collision) was simply 1ml^2. That is the constant for a hollow cylinder. The problem specifies that the object is a ball, so the cylinder classification makes no sense, and also I'm pretty sure clay is rather dense...
  39. E

    Circular Motion Question: Change in Vector Angular Velocity

    Hi i am e-pie's brother and he let me use his account.Since $$\vec{\omega}$$ is always perpendicular to the plane.Shouldn't this be $$0^o$$?
  40. kevv11

    Merry Go Round conservation of angular momentum

    So, I was reading my textbook in the section regarding net torque, and they gave an example of a seesaw with one person at each end, and they said that there is a net external torque due to the force of gravity on each person. I completely understand that; however, when I was reading another...
  41. sergiokapone

    A Index Juggling: Angular Momentum Tensor & Inertia Tensor in 3D-Space

    Lets consider the angular momentum tensor (here ##m=1##) \begin{equation} L^{ij} = x^iv^j - x^jv^i \end{equation} and rortational velocity of particle (expressed via angular momentum tensor) \begin{equation} v^j = \omega^{jm}x_m. \end{equation} Then \begin{equation} L^{ij} =...
  42. M

    Kinetic Energy & Intrinsic Angular Momentum

    I had a question about the equation (1/2)mv^2... Why is the velocity squared? Why not simply (1/2)mv? Does it have anything to do with the intrinsic angular momentum ie does the intrinsic angular momentum change in anyway as velocity increases in a particular reference frame leading to the...
  43. D

    Angular momentum of a system relative to a moving reference frame.

    I don't have too much of a clue of how to begin the problem. I first wrote the angular moementum of the system of particles: →M=∑mi(→ri×→vi)M→=∑mi(r→i×v→i). Then I know that the angular momentum from of the moving reference frame would have the velocity as the sum of the velocity of the frame...
  44. P

    Can l Be Equal to 4 in Quantum Numbers?

    n is the principal quantum number. l is the angular momentum quantum number. ml is the magnetic quantum number. The possible values of l are 2, 3, and 4. I'm not sure if l can be equal to 4. On the answer key, it shows l = 2, 3.
  45. PhysicS FAN

    Understanding Force and Momentum in Angular Elastic Collisions

    The speed of the sphere after the impact will be the same since the collision is elastic and the kinetic energy remains the same. So the change of momentum will be given by the cosine law right? What bothers me is the second question about the force that acts on the sphere (which can be given by...
  46. Np14

    What is the angular acceleration of this cylindrical system?

    PART B ONLY: The cylinder undergoes torque when the mass m2 is removed: τNET = Iα = FNETr = 45α = FT(0.5) FT = 90α, therefore msystem = 90 kg After this step, I am not sure what to do. τ = ΣF = Fg - Ft = ma = (20 kg)(9.8 m/s2) - (90α) = 196 -...
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