Moment of Inertia using Triple Integral

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To compute the moment of inertia around the z-axis for the solid unit box [0,1]x[0,1]x[0,1] with a density of δ = x² + y² + z², the relevant formula is I = ∫∫∫ r² δ dV, where r² is defined as x² + y². The integration bounds for each variable are straightforward, ranging from 0 to 1 for x, y, and z. The suggested setup for the integral is ∫₀¹ ∫₀¹ ∫₀¹ (x² + y²)(x² + y² + z²) dz dy dx. The order of integration does not affect the outcome due to the independence of the boundaries.
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Homework Statement


Compute the moment of inertia around the z-axis of the solid unit box [0,1]x[0,1]x[0,1] with density given by \delta=x^{2}+y^{2}+z^{2}.


Homework Equations


I=\int\int\intr^{2} \delta dV


The Attempt at a Solution


I know that the distance r^{2} from the z-axis would be x^{2}+y^{2}. I don't know how to determine the bounds and the order of the three integrals. Could someone please explain to me how to determine which order I should integrate, and then how I go about finding the bounds of integration for each of the three integrals.

Thanks!
 
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Since none of the boundaries on your volume is dependent on each other you can just write it as a simple 'volume' integral if you want to think of it that way, as if you're finding the volume of the cube but with the other terms involved: r^{2} and {\delta}

So in my mind it should be set up as follows:

\int_{0}^{1}\int_{0}^{1}\int_{0}^{1}(x^{2}+y^{2})(x^{2}+y^{2}+z^{2})dzdydx

The order of integration won't matter.
 
Oh, that's much easier than I was trying to make it. Thank you!
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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