How Do You Calculate the Moment of Inertia of a Ceiling Fan?

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SUMMARY

The moment of inertia of a ceiling fan can be calculated using Newton's second law for rotation. Given an angular speed of 2.40 rad/s and a frictional torque of 0.227 Nm that brings the fan to a stop in 6.65 seconds, the angular acceleration can be determined first. By applying the relationship between torque, moment of inertia, and angular acceleration, the moment of inertia can be deduced without needing the radius of the fan.

PREREQUISITES
  • Understanding of angular kinematics
  • Familiarity with Newton's second law for rotation
  • Knowledge of torque and its relationship to angular acceleration
  • Basic principles of rotational motion
NEXT STEPS
  • Calculate angular acceleration using the formula α = (ω_final - ω_initial) / time
  • Apply the formula τ = I * α to find the moment of inertia
  • Explore the concept of rotational kinetic energy using K = 1/2 I ω^2
  • Study examples of calculating moment of inertia for various shapes and objects
USEFUL FOR

Physics students, mechanical engineers, and anyone interested in understanding rotational dynamics and calculating moment of inertia in practical applications.

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Homework Statement



When a ceiling fan rotating with an angular speed of 2.40 rad/s is turned off, a frictional torque of 0.227 Nm slows it to a stop in 6.65 s. What is the moment of inertia of the fan?


Homework Equations





The Attempt at a Solution



In almost all of the moment of inertia equations, they involve a radius. there is no radius given in the problem. i tried to use K= 1/2 I w^2. I am really stuck and don't know what to do next.
 
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You don't have the data to compute the moment of inertia directly. Instead, deduce the moment of inertia by applying Newton's 2nd law for rotation. Hint: First compute the angular acceleration using kinematics.
 
Thanks so much! i just got it right on the webassign
 

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