Moment of inertia, Sphere. New method.

In summary, the moment of inertia of a sphere can be calculated using many different methods, with the most common involving calculus. It is possible that there are more than 18 methods, as mentioned by the professor, with at least 4 involving calculus (disk, sphere, and shell). Variations may exist within the two methods using discs, and there is interest in learning about the approach using a sphere.
  • #1
jaeoos
3
0
Q. Show the moment of inertia of sphere is 2/5mR^2
using many different methods.

My professor said he knew 18 different method.
Do you have a new idea?
Tell me anything you know. I hope one of your methods will be the 19th method.
 
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  • #2
Perhaps your professor was referring to experimental methods of finding moment of inertia of a solid sphere ( I am sure there are more than 18).
The only method, by way of proof, that I know of involves calculus.
 
  • #3
I have found 4 methods involving calculus.
calculus from disk(2 methods), sphere and shell.
 
  • #4
Your two methods using discs, how do they vary ?
Also I would like to know your approach using a sphere .
 

1. What is moment of inertia in relation to a sphere?

Moment of inertia is a measure of an object's resistance to changes in its rotational motion. It is similar to mass in linear motion, but for rotational motion. In the case of a sphere, it represents the distribution of mass around its axis of rotation.

2. How is moment of inertia calculated for a sphere?

For a solid sphere, the moment of inertia is given by the formula I = (2/5) * m * r^2, where m is the mass of the sphere and r is the radius. This formula assumes that the sphere has a uniform density and is rotating around its center.

3. What is the new method for calculating moment of inertia for a sphere?

The new method for calculating moment of inertia for a sphere involves using numerical integration techniques. This method takes into account the varying density of the sphere and allows for more accurate calculations.

4. How does the new method for calculating moment of inertia for a sphere differ from the traditional method?

The traditional method for calculating moment of inertia only applies to objects with a uniform density, while the new method takes into account the varying density of a sphere. Additionally, the new method uses numerical integration, which allows for more precise calculations.

5. What are the practical applications of understanding moment of inertia for a sphere?

Understanding moment of inertia for a sphere is important in fields such as physics, engineering, and astronomy. It can be used to analyze the rotational motion of objects in these fields and to design structures and machines that require rotational motion. It also helps in understanding the behavior of celestial bodies, such as planets and stars.

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