Question

question number 2




please solve it properly with steps

Answer 1

nglass=Cair/Cglass
3/2=Cair/2×10^8
Cair=(3×2×10^8)/2
Cair=3×10^8 m/s
NOW,
Cair/Cwater=refractive index of water wrt.air
3×10^8/Cwater=4/3
Cwater=(3×3×10^8)/4
Cwater=2.25×10^8 m/s

therefore speed of light in water is 2.25×10^8 m/s
and
speed of light in vacuum is 3×10^8 m/s.