Question

imagine that an electromagnetic wave traveled through each of the mediums listed below for exactly 1 second. put the mediums in order by the distance the wave would travel, from the greatest distance (at the top) to the shortest distance (at the bottom).

Explanation:

Step1: Recall the speed of electromagnetic waves in different mediums

The speed of electromagnetic waves in empty space (vacuum) is the fastest, approximately \(c = 3\times10^{8}\text{ m/s}\). The refractive index \(n\) of a medium is related to the speed of light \(v\) in the medium by the formula \(n=\frac{c}{v}\), where \(c\) is the speed of light in vacuum. The refractive index of water \(n_{water}\approx1.33\), so \(v_{water}=\frac{c}{n_{water}}\approx\frac{3\times 10^{8}}{1.33}\approx2.26\times 10^{8}\text{ m/s}\). The refractive index of glass \(n_{glass}\approx1.5\), so \(v_{glass}=\frac{c}{n_{glass}}=\frac{3\times 10^{8}}{1.5} = 2\times 10^{8}\text{ m/s}\). The refractive index of diamond \(n_{diamond}\approx2.42\), so \(v_{diamond}=\frac{c}{n_{diamond}}=\frac{3\times 10^{8}}{2.42}\approx1.24\times 10^{8}\text{ m/s}\).

Step2: Use the formula \(d = v\times t\)

Since \(t = 1\text{ s}\), \(d=v\). The greater the speed \(v\) of the electromagnetic wave in the medium, the greater the distance \(d\) it travels in \(t = 1\text{ s}\).

Answer:

Empty space, Water, Glass, Diamond