A long, thin straight wire with linear charge density ? runs down the center of a thin, hollow metal cylinder of radius R. The cylinder has a net linear charge density

2?.

Assume ? is positive. Find expressions for the electric field strength. In what direction does the electric field point in each of the cases? (Use any variable or symbol stated above along with the following as necessary: r and ?0.)

(a) inside the cylinder, r < R

Magnitude E =

Direction=

(b)outside the cylinder, r > R

Magnitude E=

Direction=