An electromagnetic wave with frequency 5.70 x 1014 Hz propagates with a speed of 2.17 x 108 m/s in a certain piece of glass. Find
(a) The wavelength of the wave in the glass;
(b) The wavelength of a wave of the same frequency propagating in air;
(c) The index of refraction n of the glass for an electromagnetic wave with this frequency;
(d) The dielectric constant for glass at this frequency, assuming that the relative permeability is unity.