Ratio of K. E. of solid cylinder to shell

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SUMMARY

The discussion focuses on the ratio of kinetic energy between a solid cylinder and a hollow cylinder. It establishes that the total kinetic energy for a solid cylinder is calculated as \( \frac{3mv^2}{4} \) using the formula for rotational and translational kinetic energy, where \( I = \frac{1}{2}mR^2 \) and \( v = \omega R \). In contrast, the total kinetic energy for a hollow cylinder is simply \( mv^2 \). The conclusion confirms that the correct opinion regarding the kinetic energy ratio is option (a).

PREREQUISITES
  • Understanding of rotational and translational kinetic energy concepts
  • Familiarity with the moment of inertia, specifically \( I = \frac{1}{2}mR^2 \)
  • Knowledge of angular velocity and its relationship to linear velocity (\( v = \omega R \))
  • Basic algebra for manipulating kinetic energy equations
NEXT STEPS
  • Study the derivation of kinetic energy formulas for different shapes, including spheres and disks
  • Learn about the conservation of energy in rigid body dynamics
  • Explore the implications of kinetic energy ratios in practical applications, such as mechanical engineering
  • Investigate the effects of mass distribution on the moment of inertia for various geometries
USEFUL FOR

Students in physics or engineering courses, educators teaching mechanics, and anyone interested in the principles of rotational dynamics and energy conservation.

Pushoam
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Homework Statement


upload_2017-12-22_11-38-41.png


Homework Equations

The Attempt at a Solution


total kinetic energy of a rigid body = rotational kinetic energy of the body around its center of mass + translational kinetic energy of center of mass

For solid cylinder, total kinetic energy = ## \frac { [I = \frac 1 2 mR^2]\omega ^2 } 2 + \frac 1 2 mv^2 = \frac { 3 mv^2} 4;~ v = \omega R ##

Similarly for hollow cylinder , total kinetic energy = ## mv^2 ##

So, the correct opinion is (a).

Is this correct?
 

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Pushoam said:
the correct opinion is (a).
yes.
 
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Thanks.
 

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