Question

Light waves are electromagnetic waves that travel at 3.00 Light waves are electromagnetic waves that travel 108 m/s. The eye is most sensitive to light having a wavelength of 5.50 Light waves are electromagnetic waves that travel 10-7 m.(a) Find the frequency of this light wave.Hz(b) Find its period.s

Answer 1

(a) $5.45 \cdot 10^{14} Hz$

The relationship between frequency and wavelength of an electromagnetic wave is given by

$c=f \lambda$

where

$c=3.00 \cdot 10^8 m/s$ is the speed of light

$f$ is the frequency

$\lambda$ is the wavelength

In this problem, we are considering light with wavelength of

$\lambda=5.50 \cdot 10^{-7} m$

Substituting into the equation and re-arranging it, we can find the corresponding frequency:

$f=\frac{c}{\lambda}=\frac{3.00 \cdot 10^8 m/s}{5.50 \cdot 10^{-7} m}=5.45 \cdot 10^{14} Hz$

(b) $1.83\cdot 10^{-15} s$

The period of a wave is equal to the reciprocal of the frequency:

$T=\frac{1}{f}$

And using $f=5.45 \cdot 10^{14} Hz$ as we found in the previous part, we can find the period of this wave:

$T=\frac{1}{5.45 \cdot 10^{14} Hz}=1.83\cdot 10^{-15} s$