A solid resin rod is a cylinder of radius and length

PHYSICS · Multi-part · Fermi University Physics · Mathematical Methods for Physics · Vector calculus and field geometry · Vector calculus and field geometry

Mathematical Methods for Physics, Ch Line, surface and volume integrals

Problem

A solid resin rod is a cylinder of radius a=0.050 ma = 0.050\,\mathrm{m} and length L=0.20 mL = 0.20\,\mathrm{m}. Manufacturing leaves it with a volume charge density that depends only on the distance ρ\rho from the rod's axis, ρq(ρ)=ρ0(1−ρa),ρ0=4.0×10−6 C m−3,\rho_q(\rho) = \rho_0\left(1 - \frac{\rho}{a}\right), \qquad \rho_0 = 4.0\times10^{-6}\,\mathrm{C\,m^{-3}}, where ρ\rho without a subscript is the cylindrical coordinate, and ρq\rho_q and ρ0\rho_0 are charge densities. ((a)) Find the total charge QQ on the rod. ((b)) What fraction of QQ lies within a distance a/2a/2 of the axis?

Browse the problem library