Also the equation I = Sum mr^2 can only be used if "a rigid body consists of a few particles", according to my book. What does that mean? Would the body be on 2D? Would it be a rectangle? Thanks!
So i read up a bit about the parallel axis theorem and I seem to have found this figure that seems to explain why the moment of inertia for the cylinder alone was 1/2mr^2. Is it just that this moment of inertia concept is an integral and so to calculate discrete sums it would be very difficult...
Well, so I know that I = sum m x r^2. I have that equation, I just don't know why I can't use it to get the correct answers.
Berkeman, I really don't appreciate the tone of your response. I would love to understand physics through the concepts and the math, but I need the answer for my online...
I finally got this problem by doing 1.2(0.72^2)/3 using yahoo answers. I just don't know why i had to divide by 3! this whole concept of moment of inertia kind of confuses me =\. Thanks.
Homework Statement
A ceiling fan consists of a small cylindrical disk with 5 thin rods coming from the center. The disk has mass md = 3.3 kg and radius R = 0.26 m. The rods each have mass mr = 1.2 kg and length L = 0.72 m.
What is the moment of inertia of each rod about the axis of rotation...
I encountered this question in a practice test for an upcoming exam. My first inkling was to answer with (C) because in uniform circular motion, the acceleration always points towards the center of the circle, but the actual answer was D. Do you think this question was just an issue of direction...