What is the angular momentum of a rotating disk and how do you calculate it?

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SUMMARY

The angular momentum of a rotating disk can be calculated using the formula L = Iω, where I is the rotational inertia and ω is the angular velocity. For a disk with a mass of 1.8 kg and a radius of 0.026 m rotating at 600 RPM, the calculated angular velocity is 62.83 rad/sec. The user initially calculated the angular momentum as 0.076 kg*m²/s, but the correct answer is 0.038 kg*m²/s, indicating a potential error in the calculation of the rotational inertia or the conversion of units.

PREREQUISITES
  • Understanding of angular momentum and its formula L = Iω
  • Knowledge of rotational inertia for solid disks
  • Ability to convert RPM to radians per second
  • Familiarity with basic physics concepts related to rotational motion
NEXT STEPS
  • Review the calculation of rotational inertia for a solid disk
  • Learn how to convert RPM to radians per second accurately
  • Explore examples of angular momentum calculations in different contexts
  • Study the effects of varying mass and radius on angular momentum
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Physics students, educators, and anyone studying rotational dynamics or preparing for physics exams will benefit from this discussion.

JSmithDawg
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Homework Statement


The 1.8kg , 5.2-cm-diameter disk is rotating as shown. What is the angular momentum of the disk about the axle?

9-33.jpg

Homework Equations


L=Iω=(mr^2)ω

The Attempt at a Solution


r=.026m
m=1.8 kg
ω=600rpm*(1minute/60seconds)*(2pi radians/1rotation) = 62.83 rad/sec

L=(1.8kg * .026m^2) * 62.83 rad/sec = .076 (kg*m^2/s). I think this is correct, but my online quiz says that the answer is .038. What am I doing wrong?
 
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