A solid right circular cylinder of radius and height has its axis along the -axis
PHYSICS · Multi-part · Fermi University Physics · Mathematical Methods for Physics · Calculus of change and accumulation · Vector calculus and field geometry
Mathematical Methods for Physics, Ch Multiple integrals and change of variables
Problem
A solid right circular cylinder of radius R=0.100m and height h=0.400m has its axis along the z-axis. Its mass density depends only on the perpendicular distance ρ from that axis, ρm(ρ)=ρm0(1−ρ/R) with ρm0=1200kgm−3, falling linearly from ρm0 on the axis to zero at the rim.
((a)) Choose coordinates for the mass integral, saying why they suit this solid, and compute the mass M.
((b)) Compute the moment of inertia I about the central (z) axis.
((c)) Evaluate I/(MR2) and compare it with the value 1/2 for a uniform cylinder, explaining the sign of the difference.