A rod of length L and mass M has a nonuniform mass distribut

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SUMMARY

The discussion focuses on calculating the moment of inertia for a rod with a nonuniform mass distribution defined by the linear mass density λ=cx², where x is the distance from the center and c is a constant. Participants emphasize the necessity of calculus to derive the expression for c and the moment of inertia. The moment of inertia for a uniform rod is referenced as 1/3ML² and 1/12ML², highlighting the importance of integration in solving the problem. A suggestion is made to first understand the moment of inertia for a uniform rod to build confidence in tackling the nonuniform case.

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  • Familiarity with the concept of moment of inertia
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Homework Statement


A rod of length L and mass M has a nonuniform mass distribution. The linear mass density (mass per length) is λ=cx2, where x is measured from the center of the rod and c is a constant.

Find the expression for c.Find the expression for the moment of inertia of the rod for rotation about an axis through the center.

Homework Equations


I do not know the equations for c or what it stands for
Moment of inertia xML^2

The Attempt at a Solution

A:? I'm cluelessB:1/3ML^2 and 1/12ML^2 I have no clue why it's not 1/3[/B]
 
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Have you taken Calculus yet? If you have an expression for mass per length, then you can multiply by Δx to get the mass of that tiny section of the rod. If you know Calculus then you should be able to set up an integral with that information.

If you do not know Calculus, then I think this question will be difficult to solve. Why don't you set up a uniform rod and perform an integration on that to get the moment of inertia. That will give you confidence that you are doing it correctly, since you can verify with known formulas.
 

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