The index of refraction of a certain glass is measured to be 1.5. What is the speed of light in that glass? $\left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$
A) $1.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$
B) $5.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$
C) $4.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$
D) $3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$
E) $2.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$

Question

Quizplus · Accepted Answer

The speed of light in a medium is given by $v = \frac{c}{n}$, where $c$ is the speed of light in vacuum (3.0 x $10^8$ m/s) and $n$ is the index of refraction. For glass with $n = 1.5$, $v = \frac{3.0 \times 10^8}{1.5} = 2.0 \times 10^8$ m/s.

The Index of Refraction of a Certain Glass Is Measured (c=3.0×108 m/s)\left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)(c=3.0×108 m/s)

The Index of Refraction of a Certain Glass Is Measured $\left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$