Question

pls answer me this fast ​

Answer 1

n-refractive index

$n \: w = \frac{c \: air}{v \: water}$

$\frac{4}{3} = \frac{3 \times {10}^{8} }{v \: w}$

$v \: w = \frac{9 \times {10}^{8} }{4} = 2.25 \: \times {10}^{8}$

I hope this helps ( ╹▽╹ )