Answer
(a) Violet
(b) $f_{blue}=6.4\times 10^{14}Hz$
$f_{red}=4.4\times 10^{14}Hz$
Work Step by Step
(a) Frequency and wavelength are inversely proportional. Thus, the shorter the wavelength, the higher the frequency. We know that the wavelength of violet light is shorter compared to that of red, so violet light has the higher frequency.
(b) The frequency of blue light is given as
$f_{blue}=\frac{c}{\lambda_{blue}}$
We plug in the known values to obtain:
$f_{blue}=\frac{3.00\times 10^8}{470\times 10^{-9}}=6.4\times 10^{14}Hz$
The frequency of red light is given as
$f_{red}=\frac{c}{\lambda_{red}}$
We plug in the known values to obtain:
$f_{red}=\frac{3.00\times 10^8}{680\times 10^{-9}}=4.4\times 10^{14}Hz$
