Angular acceleration of dipole in uniform electric field

AI Thread Summary
The discussion focuses on calculating the moment of inertia for a dipole in a uniform electric field, specifically addressing a massless rod with two massive point particles. The initial calculation of the moment of inertia is challenged, emphasizing that the rod does not contribute to it. The correct formula for the moment of inertia is derived as I = ML^2/2, based on the distances of the point masses from the center of rotation. Participants seek clarification on whether this calculation is accurate. The conversation highlights the importance of correctly identifying contributing masses in moment of inertia calculations.
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1. The problem statement, and my attempt at a solution is given in pic

Please help me.
 

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At first glance, you're moment of inertia is incorrect. The rod is massless and therefore does not contribute to the moment of inertia. Your moment of inertia comes from the two massive point particles a distance, L/2, away from the center of rotation.
 
G01 said:
At first glance, you're moment of inertia is incorrect. The rod is massless and therefore does not contribute to the moment of inertia. Your moment of inertia comes from the two massive point particles a distance, L/2, away from the center of rotation.

Yes, so ...

moment of inertia, I = \sum m_ir_i^2 = \frac{ML^2}{4} \ + \ \frac{ML^2}{4}

So I \ = \ \frac{ML^2}{2}

Is that wrong?
 
someone help please
 
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