1. D

    Hi :) new here, to ask an angular velocity question

    Well, hello everyone. I will be honest. I basically registered here, to get a question answered which is bothering me a lot lately. Would be really nice if someone could help me a little. So lets cut right to the case :) Assuming you have an aircraft with a propellor on each wing. And...
  2. S

    angular acceleration

    Hi :) I need some help with this: The grinding disc of a grinding machine starts from a rest and has a constant angular acceleration for the first 10 rotations. a) It uses 0.87 s on its second rotation. how long does it use on the first rotation? Her i found out that it use 0.62s on...
  3. A

    Rotational Power = torque (τ)*(ω) angular velocity? - Problem with units

    I set up an experiment with a pendulum (uniform beam) swinging on a hinge and the hinge attached to a small PMDC generator. The generator had no load attached and its output voltage is proportional to its speed of rotation. I swung the pendulum from 90 degrees and using a data logger I...
  4. O

    Confusion with angular magnification

    The angular magnification defined as, angle subtended by image of object /angle subtended by object when 25 cm from the naked eye Consider this. An object is placing 50cm in front of a convex lens which has a focus length of 100cm. So the image will create 100cm in front of the lens. If we...
  5. E

    Need help with an angular momentum problem? I have it solved but apparently I'm wrong

    I've spent at least 1.5 hours on this problem trying to figure out what i did wrong and I can't find anything. With an exam in two days plus another chapter to go through. Regardless, here are the problem(6) and answer, as well as my work. Hope you can read it, and the writing on the bottom...
  6. L

    Calculate a derivation of a the angular speed of a solid body

    I am practicing for a mechanics exam. Please find the problem and solution in the image: I am not able to reach the solution. The question is to derivate an expression of the angular speed to obtain the angular acceleration. The angular speed is a function of the rotation angle, so...
  7. B

    Angular motion problem

    Problem A long string is wrapped around a 5.00-cm-diameter cylinder, initially at rest, that is free to rotate on an axle. The string is then pulled with a constant acceleration of 1.50 m/s2 until 1.25 m of string has been unwound. Assume the string unwinds without slipping. (a) What is the...
  8. avito009

    Earths angular momentum and newtons second law.

    Newtons second law states: A force applied to an object changes its state of motion. If the object is at rest, it will start moving. If it is moving, it will speed up, slow down, or change direction. The change in motion depends on the mass of the object. Can we interpret this way? The earth...
  9. G

    What is torque divided by angular velocity?

    What is the best way to simplify torque as a proportion of angular velocity? Is that even a thing? Is there something close?
  10. E

    Sun's rotation angular velocity.

    Hi: I made a formula to find the angular velocity with which the shade rotates about one's position during one day, assuming the Sun rotates with constant angular velocity $\omega$ in a plane at an angle $\alpha$ with respect to the plane of the horizon. I got $\Omega = (1+tan^2 \omega t)...
  11. A

    Angular displacement problem

    Hey! I'm having trouble relating the info given with the answers they want... A small object with mass 3.20 kg moves counterclockwise with constant speed 5.70 m/s in a circle of radius 4.90 m centered at the origin. It starts at the point with position vector (4.90i hat + 0 j) m. Then it...
  12. K

    Angular momentum in orbital mechanics

    Depending on whether you use the sun or earth as the centre of your reference frame (origin of co-ordinate system) can result in different answers for the calculation of angular momentum. Is there a preferred reference point for the calculation of such a value? In a two body system is it the...
  13. B

    【exam] electron's angular velocity

    I only know w= eB/m, and how can I calculate dw? ------------------------------------------------ As described in the Bohr model, an electron is circularly orbiting a proton in a hydrogen atom with radius r and velocity v. The orbital angular momentum of the electron is in the + z...
  14. B

    [exam problem] angular momentum problem

    A particle of mass m travels in a horizontal circle of radius R on a frictionless table. The centripetal force is provided by a string passing through a hole in the table attached to two blocks of equal mass M, as shown in the figure. If one hanging block is removed, what will the radius of the...
  15. P

    Finding angle between L and S angular momentum.

    In a many electron atom the orbital spin and total angular momenta are denoted by L,S and J respectively.If L=2, S=1, and J=2, find the angle between L,S using vector atomic model. Attempt: J=L+S J.J=|L|^2 +|S|^2 + 2|L|.|S| cosθ. So cosθ= [|J|^2 -|L|^2-|S|^2]/ [2|L|.|S| ] Now |L|=([L...
  16. B

    rotational speed and angular momentum

    Require help to understand the following physics concept What happens to the rotational speed and angular momentum, when spinning system contracts in the absence of an external torque? weather rotational speed and angular momentum changes or not? if changes how do they change? Please...
  17. dokrbb

    T find the angular momentum

    Can you suggest me please how to set my equations in order to get the angular momentum in this problem? A particle of mass m moves in a circle of radius R at a constant speed v, as shown below. The motion begins at point Q at time t = 0. Determine the angular momentum of the particle...
  18. R

    Angular frequency

    A mass moves along the x axis with potential energy U(x)= - U0 a^2 / (a^2 + x^2). What is the angular frequency assuming the oscillation is small enough to be harmonic? w^2 = k/m with w as the angular frequency F= -kx = -(gradient) U Since this is one-dimensional we take the derivative of...
  19. W

    Measurements of angular momentum components

    If I make a measurement of Lz, and then make a measurement of Lx, then this value will not be deterministic, but how can I calculate the possible values that Lx can take? Then if I make another measurement of Lz after the Lx measurement, what are the possible values of this? I think that this...
  20. S

    Linear Speed? Angular Speed? Centripetal Acceleration?

    a toy car moves around a circular track that has a diameter of 1.2m. It makes one complete revolution in 12secs. calculate the linear speed, angular speed and centripetal acceleration. can u pls tell me how to answer that?