Question

3. The polarizing (or Brewster) angle is defined as the angle of incidence at a boundary between two media, for which the reflected and the refracted rays are perpendicular to each other. If the polarizing angle for light traveling in air reflecting off a certain type of glass is 53°, what is the speed of light in the glass? a) 1.80×108 m/s b) 1.60×108 m/s c) 2.26×108 m/s d) 2.52×108 m/s e) 2.02×108 m/s

Answer 1

Speed of light in the glass
`v=2.26* 10^8 ms^(-1)`

Step-by-step explanation:

In this question we have given

angle of polaization,p=
`53^o`

we have to find the speed of light in the glass,v=?

We know that, refractive index of glass can be determined by following formula

`n=(c)/(v)`................(1)

here,

c- speed of light in air

v-speed of light in glass

we also know according to brewester's law refrective index of glass is given as

n=tanp......................(2)

here p-angle of polarization

From equation (1) and equation (2)

we got

`(c)/(v)=tanp`

put value of c=
`3* 10^8 ms^(-1)` and p=
`53^o` in equation 3

we got

`(3* 10^8 ms^(-1))/(v)=tan53`

`v=(3* 10^8 ms^(-1))/(tan53)\\v=(3* 10^8 ms^(-1))/(1.32)\\v=2.26* 10^8 ms^(-1)`