Question

The absolute refractive index of a glass and water are 4/3 and 3/2 respectively . if the speed of light in glass is 2×10 power of 8 m/s ,caculate the speed of light in (1) vacuum (2) water

Answer 1

(1) Refractive Index of glass=Speed of light in vaccum/Speed of light in glass
                                   4/3=x/2×10⁸
                                   4/3×2×10⁸=x
 Speed of light in vaccum  = 2.666 × 10⁸  OR 2.67 × 10⁸  m/sec       
             
Refractive Index of water=Speed of light in vaccum/Speed of light in water
                                  3/2 = 4 ×2×10⁸/x×3
                                   On solving,
    Speed of light in water= 1.777×10⁸ OR 1.78 × 10⁸m/sec