(a) Show that the skin depth in a poor conductor (o « we) is (2/0)JE/µ (independent offrequency). Find the skin depth (in meters) for (pure) water.(b) Show that the skin depth in a good conductor (ơ » we) is à /27 (where à is the wavelengthin the conductor). Find the skin depth (in nanometers) for a typical metal (a 107 (2 m)-')in the visible range (» z 1015/s), assuming e = €o and µ z µo. Why are metals opaque?

(a) Show that the skin depth in a poor conductor (a « wx) is (2/0)VElµ (independent of frequency). Find the skin depth (in meters) for (pure) water. (b) Show that the skin depth in a good conductor (a » we) is À /2r (where à is the wavelength in the conductor). Find the skin depth (in nanometers) for a typical metal (a z 10" (2 m) –1) in the visible range (w× 101>/s), assuming e = €o and µ = µ0. Why are metals opaque?

(a) Show that the skin depth in a poor conductor (a « wx) is (2/0)VElµ (independent of frequency). Find the skin depth (in meters) for (pure) water. (b) Show that the skin depth in a good conductor (a » we) is À /2r (where à is the wavelength in the conductor). Find the skin depth (in nanometers) for a typical metal (a z 10" (2 m) –1) in the visible range (w× 101>/s), assuming e = €o and µ = µ0. Why are metals opaque?