Answer
(a) The wavelength inside the glass is $455~nm$
(b) The frequency of the light inside the glass is $4.34\times 10^{14}~Hz$
Work Step by Step
(a) We can find the wavelength $\lambda'$ inside the glass:
$\lambda' = \frac{\lambda_0}{n}$
$\lambda' = \frac{692~nm}{1.52}$
$\lambda' = 455~nm$
The wavelength inside the glass is $455~nm$
(b) The frequency of a wave does not change when the wave moves from one medium into another medium. We can find the frequency of the light in air:
$f = \frac{c}{\lambda_0}$
$f = \frac{3.0\times 10^8~m/s}{692\times 10^{-9}~m}$
$f = 4.34\times 10^{14}~Hz$
Since the frequency of the light does not change, the frequency of the light inside the glass is $4.34\times 10^{14}~Hz$.
