Question

the refractive index of water to vaccuum is 4/3 and refractiveindex of vacuum with respect to glass is 2/3. if the speed of light in glass is 2multiply 10^-8 m/s then find the speed of light in vaccuum and in water

Answer 1

refractive index of water to vacuum = 4/3
refractive index of vacuum to glass = 2/3
refractive index of glass to vacuum will be = 3/2

refractive index of glass to water = (3/2)/(4/3) = 3*3/4*2 = 9/8
⇒ speed of light in water/speed of light in glass = 9/8
⇒ speed of light in water / 2*10⁸ = 9/8
⇒ speed of light in water = 2*10⁸*9/8
⇒ speed of light in water = 2.25*10⁸ m/s

refractive index of water to vacuum = 4/3
⇒ speed of light in vacuum/speed of light in water = 4/3
⇒ speed of light in vacuum / 2.25*10⁸ = 4/3
⇒ speed of light in vacuum = 2.25*10⁸*4/3
⇒ speed of light in vacuum = 3*10⁸ m/s

Answer 2

hope this answer will help u