Light traveling from water to a gemstone strikes the surface at an angle of 80.0º and has an angle of refraction of 15.2º . (a) What is the speed of light in the gemstone? (b) What is unreasonable about this result? (c) Which assumptions are unreasonable or inconsistent?

Respuesta :

Answer:

a

The the speed of light in the gemstone is  [tex]v= 0.599*10^8 m/s[/tex]

b

The unreasonable thing about this is that the speed of ligth in the gemstone is too low

the speed is 19% of the speed of light  which is very low

c

One main unreasonable or inconsistent factor is that the assumption that the  differnce between the angle of incidence and angle of refraction is  very large

Explanation:

  From the question we are told that

       The  angle of incidence  [tex]i = 80^o[/tex]

        The angle of refraction  [tex]r = 15.2^o[/tex]

From Snell's law we have ,

      [tex]n_1 sin \theta_1 = n_2 sin \theta_2[/tex]

    Where [tex]n_1[/tex] is the refractive index of the first medium (water) with a constant value  of  [tex]n_1 = 1..333[/tex]

                [tex]n_2[/tex]  is the refractive index of the second medium (gem stone)

                 [tex]\theta_1[/tex] is the angle between  the beam and perpendicular surface of the first medium

               [tex]\theta_2[/tex]  is the angle  between the beam an the perpendicular surface of the second medium

      Making  the [tex]n_2[/tex] the subject of the formula

                       [tex]n_2 = n_1 \frac{sin \theta_1}{sin \theta_2}[/tex]

                           [tex]= (1.333)(\frac{sin (80.0)}{sin 15.2} )[/tex]

                           [tex]= 5.007[/tex]

 Generally refractive index of a material  is mathematically represented

                      [tex]n = \frac{c}{v}[/tex]

 Where c is the speed light

               v is the speed of light  observed in a medium

 Making v the subject

            [tex]v = \frac{c}{n}[/tex]

 substituting value for gem stone

          [tex]v = \frac{3.0*10^8}{5.007}[/tex]

              [tex]v= 0.599*10^8 m/s[/tex]