Answer:
to create the particle the speed must be greater than 2.25 10⁸ m / s
Step-by-step explanation:
In this exercise we must use the relation of the index of refraction with the speed of light in a vacuum and a material medium
n = c / v
where c is the speed of light in the vacuum, v the speed of light in the material medium and n the ratio of rafraccio
in this case they give us that the medium matter water them that has a refractive index of
n = 1,333
we clear
v = c / n
let's calculate
v = 3 10⁸ / 1,333
v = 2.25 10⁸ m / s
to create the particle the speed must be greater than 2.25 10⁸ m / s