P8-1

The solid shown is made by revolving the triangular area around the vertical axis shown. If the solid has a mass of 2kg and the dimensions are in centimeters, determine its mass moment of inertia about the central axis. Determine the radius of gyration. Does this value fall between necessary extremum?

Suggestion: Create thin rings of variable height y and variable distance from the axis r. A thin ring has a known elemental inertia dI = dm r^2. Integrate from r-inner to r-outer