document.write( "Question 1182678: The area bounded by y = 3, x = 2, y = -3 and x = 0 is revolved about the y-axis.
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document.write( "The moment of inertia of the solid is \n" );
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Algebra.Com's Answer #849911 by CPhill(1959)![]() ![]() You can put this solution on YOUR website! Here's how to calculate the moment of inertia of the solid:\r \n" ); document.write( "\n" ); document.write( "1. **Describe the shape:** The region bounded by y = 3, x = 2, y = -3, and x = 0 is a rectangle. When revolved about the y-axis, this rectangle forms a hollow cylinder (or a cylindrical shell).\r \n" ); document.write( "\n" ); document.write( "2. **Dimensions of the cylinder:** \n" ); document.write( " * Inner radius (r₁): 0 \n" ); document.write( " * Outer radius (r₂): 2 \n" ); document.write( " * Height (h): 3 - (-3 We are not given a density, so we'll assume a uniform density (ρ). Then, we will find the moment of inertia *in terms of ρ*. If you're given a density, you would multiply by it at the end to get a numerical moment of inertia.\r \n" ); document.write( "\n" ); document.write( "4. **Moment of Inertia of a hollow cylinder:** The moment of inertia (I) of a hollow cylinder about its central axis is given by the formula:\r \n" ); document.write( "\n" ); document.write( " I = (1/2) * m * (r₁² + r₂²)\r \n" ); document.write( "\n" ); document.write( " where m is the mass of the cylinder.\r \n" ); document.write( "\n" ); document.write( "5. **Mass in terms of density and volume:** The mass of the cylinder is equal to the product of its density and volume. \n" ); document.write( " * The volume of the hollow cylinder is given by V = πh(r₂² - r₁²) \n" ); document.write( " * Volume: V = π * 6 * (2² - 0²) = 24π \n" ); document.write( " * Thus, the mass m = ρ * V = 24πρ\r \n" ); document.write( "\n" ); document.write( "6. **Substitute and calculate:**\r \n" ); document.write( "\n" ); document.write( " I = (1/2) * (24πρ) * (0² + 2²) \n" ); document.write( " I = 12πρ * 4 \n" ); document.write( " I = 48πρ\r \n" ); document.write( "\n" ); document.write( "Therefore, the moment of inertia of the solid is $\boxed{48\pi\rho}$. If the density (ρ) were given, you would multiply by that value to find the numerical moment of inertia. \n" ); document.write( " \n" ); document.write( " |