What is Angular speed: Definition and 278 Discussions

In physics, angular frequency ω (also referred to by the terms angular speed, radial frequency, circular frequency, orbital frequency, radian frequency, and pulsatance) is a scalar measure of rotation rate. It refers to the angular displacement per unit time (for example, in rotation) or the rate of change of the phase of a sinusoidal waveform (for example, in oscillations and waves), or as the rate of change of the argument of the sine function.
Angular frequency (or angular speed) is the magnitude of the vector quantity angular velocity.One revolution is equal to 2π radians, hence




ω
=



2
π

T


=

2
π
f

,


{\displaystyle \omega ={\frac {2\pi }{T}}={2\pi f},}
where:

ω is the angular frequency or angular speed (measured in radians per second),
T is the period (measured in seconds),
f is the ordinary frequency (measured in hertz) (sometimes symbolised with ν).

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  1. S

    Angular speed people walking problem

    Homework Statement Two people start at the same place and walk around a circular lake in opposite directions. One has an angular speed of 1.7*10-3 rad/s, while the other has an angular speed of 3.4*10-3 rad/s. How long will it be before they meet? Homework Equations w=\theta/Delta t...
  2. S

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    A 3.0-m-diameter merry-go-round with rotational inertia 120 kg*m2 is spinning freely at 0.60 rev/s. Four 25-kg children sit suddenly on the edge of the merry-go-round. (a) Find the new angular speed in rev/s. (b) Determine the total energy lost to friction between the children and the...
  3. V

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    Homework Statement A truck has acceleration A. Its door has a width w and a heigth h. We want to find the angular speed of the door when it reaches the horizontal. (I attached the problem as an image) Homework Equations See solution attempt. The Attempt at a Solution There is a fictitious force...
  4. H

    Calculating Angular Speed of Playground Merry-Go-Round

    Homework Statement A playground merry-go round of Radius R=2.00m has a moment of inertia I = 250 kg.m^2 and is rotating at 10.0 rev/min about a frictionless vertical axle. Facing the axle a 25.0kg child hops onto the merry go round and manages to sit down on the edge. What is the new...
  5. S

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    Homework Statement Express each of the following in radians per second: (a) 720 ; (b) 50 ; (c) 1000 ; (d) 1 (which is the angular speed of Earth in its orbit). Homework Equations why all my answers are wrong? please help me! The Attempt at a Solution
  6. J

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  7. C

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  8. L

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  9. M

    Angular Speed of Clock Minute Hand: Rad/s

    Homework Statement What is the angular speed of the tip of the minute hand on a clock, in rad/s? Homework Equations I thought the equations needed would be angular velocity= change of theta/change in time. The Attempt at a Solution I worked on this one and am sure it has a...
  10. C

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    Hi all, my homework question is this: 1. What is the angular speed in rad/s of a point on the equator of venus? (Rotation period: 243 days) 2. What is the angular speed in rad/s of a point on the surface of venus at latitude 11 degress south? I know this isn't that difficult but I can't...
  11. B

    Can a Laser Beam Move Faster Than Light Across the Moon's Surface?

    Homework Statement You point a laser flashlight at the moon producing a spot of light on its surface. At what minimum angular speed must you sweep the laser beam in order for the light spot to streak across the moon's surface with speed v>c? Why can't you transmit information between...
  12. C

    Calculating Angular Speed of a Yo-Yo

    Hi~ This is the question i got A yo-yo has radius 8.00cm and mass 0.180kg with small hoop. The yo-yo is released at rest and after yo-yo descended 75.0cm calculater the angular speed of the rotating yo-yo and the speed of its center. I tried to use K=1/2Mv^2+1/2IW^2 but i got weird...
  13. S

    What angular speed is the stick spinning after the collision?

    Homework Statement A uniform stick 1.0 m long with a total mass of 220 g is pivoted at its center. A 3.2 g bullet is shot through the stick midway between the pivot and one end The bullet approaches at 250 m/s and leaves at 140 m/s With what angular speed is the stick spinning after the...
  14. J

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    1. A wheel 2.00m in diameter lies in a vertical plane and rotates with a constant angular acceleration of 4.00 rad/s^2. The wheel starts at rest at t=0, and the radius vector of a certain point P on the rim makes an angle of 57.3 with the horizontal at this time. At t=2, find the angular speed...
  15. S

    Angular Speed and Energy Conservation

    [SOLVED] Angular speed problem Homework Statement A cylinder with mass m1 = 4.00kg, and radius 30cm, rotates about a vertical, frictionless axle with angular velocity of 8.00 rev/s. A second cylinder, this one have a mass of m2 = 3.00kg, and radius 20cm, initially not rotating, drops onto...
  16. F

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    let's say a wheel rotates with a constant angular acceleration. Would its angular speed be affected if the radius was changed? It seems that angular speed would be independent of the radius since the angle is just a proportional quantity.
  17. S

    Angular speed of wrapper string

    Homework Statement A string is wrapped several times around the rim of a small hoop with radius 8.00 cm and mass 0.180 kg . The free end of the string is held in place and the hoop is released from rest (the figure ). After the hoop has descended 60.0 cm, calculate angular speed and...
  18. K

    Angular Speed of Sign Before Impact: Kevin's Solution

    A thin, uniform, rectangular sign hangs vertically above the door of a shop. The sign is hinged to a stationary horizontal rod along its top edge. The mass of the sign is 2.40 kg and its vertical dimension is 45.0 cm. The sign is swinging without friction, becoming a tempting target for children...
  19. N

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    [SOLVED] Angular Speed \tau = r * F Homework Statement youve got our bicycle upside-down for repairs with its 66 cm diameter wheel spinning freely at 230 rpm. the mass of the wheel is 1.9 kg and is concentrated mostly at the rim. you hold a wrench against the tire for 3.1s with a normal...
  20. J

    How Many Revolutions Does the Wheel Make in 2.33 Seconds?

    Homework Statement As a result of friction, the angular speed of a wheel changes with time according to d θ/d t = ω_0 e^(−σ t) , where ω0 and σ are constants. initial angular speed = 5.45 rad/s σ =.23913 Determine the number of revolutions the wheel makes after 2.33 s . Answer in units of...
  21. C

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  22. C

    How Fast Does a Spinning Disk Rotate After One Full Revolution?

    Homework Statement A disk with a radial line painted on it is mounted on an axle perpendicular to it and running through its center. It is initially at rest, with the line at theta 0 = -90°. The disk then undergoes constant angular acceleration. After accelerating for 3.1 s, the reference...
  23. K

    Angular Speed of a drive train

    1. The figure below shows the drive train of a bicycle that has wheels 67.3 cm in diameter and pedal cranks 17.5 cm long. The cyclist pedals at a steady angular rate of 76.5 rev/min. The chain engages with a front sprocket 15.2 cm in diameter and a rear sprocket 7.25 cm in diameter. 2. v...
  24. S

    Finding angular speed of a thin rod.

    Homework Statement A thin 1.0-meter-long rod pivoted at one end falls (rotates) from a horizantal position, starting from rest and with no friction. What is the angular speed of the rod when it is vertical? Homework Equations I (of the thin rod) = (1/3)ML^2 The Attempt at a...
  25. D

    How can you find angular speed

    How can you find angular speed (average), if its a question of rotation about a fixed axis, and all you know really is the rotational inertia of the system? You have no values of the angles (with regards to the reference axis) and no values for time either.
  26. B

    Merry-go-round angular speed physics

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  27. R

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  28. H

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  29. I

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  30. H

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  31. H

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  32. D

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  33. C

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  34. T

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  35. T

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  36. C

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  37. B

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  38. S

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  39. S

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  40. A

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  41. A

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  42. S

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  43. T

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  44. P

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  45. P

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  46. S

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  47. A

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  48. M

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  49. K

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  50. S

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