The critical angle between a medium and air is 430. What is the speed of light in that medium?

The speed of light is that medium is 281907786.2 m/s.

Explanation:

since the critical angle is Фc = 430, we know that the refractive index is given by:

n = 1/sin (Фc)

= 1/sin (430)

= 1.06

then if n is the refractive index of the medium and c is the speed of light, then the speed of light in the medium is given by:

v = c/n

= (3*10^8) / (1.06)

= 281907786.2 m/s

Therefore, the speed of light is that medium is 281907786.2 m/s.