Moment of inertia of 3-mass system

AI Thread Summary
The discussion revolves around calculating the moment of inertia for a rigid 3-mass system with masses positioned along a 6 m length. The first part of the problem was successfully completed, while the second part required finding the moment of inertia about a new axis located 2.3 m from the leftmost mass. The calculation presented includes the contributions from each mass based on their distances from the new axis. The final result calculated was 98.99 kg·m², which the poster later confirmed as correct. The focus remains on the application of the moment of inertia formula to a multi-mass system.
DrMcDreamy
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Homework Statement


This is a two part problem, I answered the first but was wondering if I did the second part right.

a) Consider a rigid 3-mass system (with origin at the leftmost mass 3 kg) which can rotate about an axis perpendicular to the system. The masses are separated by rods of length 3 m, so that the entire length is 6 m. 3.8

b) Now consider a rotation axis perpendicular to the system and passing through the point x0 at a distance 2.3 m from the leftmost mass 3 kg.
Find the moment of inertia of the 3-mass system about the new axis. Answer in units of kg · m2.

Homework Equations



I= \summiri2

The Attempt at a Solution



I= (3 kg)(2.3)2 + (2 kg)(.7)2 + (6 kg)(3.7)2 = 98.99

Is this correct?
 
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Forget it, I realized my work is right :smile:
 

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